


i r U It 



.1" 



i! ^' 'f. 






mm 



»ili: 









Machinery Pattern Making 

CONTAINING 

FULL SIZE PROFILES OF GEAR TEETH 

AND 

Fine Engravings on Full-Page Plates, Illustrating Manner of 

Constructing Numerous and Important 

Patterns and Core Boxes 




p. S. 'DINGEY 



ASSOCIATE MEMBER OF AMEUICAN SOCIETY MECHANICAL ENGINEER; 



417 dfine Ifllustrations 



SECOND EDITION. REVISED AND ENLARGED 
first thousand 




NEW YORK 
JOHN WILEY & SONS 



lS(o\ "2- 



53 E. Tenth Street 
1894 



-f- 



Copyright, 1894 
By p. S. dingey 



X' 



i^y 



'i'%111 



NOTE 



Most of the matter in this book was written expressly 
for the Ajfierican Machinist, to whose courtesy we are 
indebted for some of the ilkistrations. Mr. Dingey 
has, however, revised many of his drawings and much 
of the matter, adding some valuable items. 

WILEY & SONS. 



PREFACE TO THE SECOND EDITION. 



In issuing this edition the author wishes to thank the 
pattern-makers, molders, and those in the machinery 
business and colleges for the appreciation given to the 
first edition, and trusts that the second will receive a 
similar patronage and consideration. It is hoped that 
among the pages added, those on double-beat valves, 
the propeller, governor valves, plug valves, and items 
for pattern-makers will increase the interest already 
shown. 

The object of this book is not so much to teach 
pattern-making, — for tliat cannot be done alone througli 
a book-.-but merely to encourage a study of the prac- 
tical. 

No cast-iron rules have been laid down, and it is 
desired that the contents be accepted as suggestions ; at 
the same time that which is given is practicable, being 
the result of practice and of over twenty years' experi- 
ence in tlie business. 

In the present volume everything of a visionary kind 
has been avoided, and the author has presented such 
subjects as he believes will be interesting to pattern- 
makers and to the machinery business generally. 



F. S. DlNCJEY 



Chicago, III., October 30, 1894. 



CONTENTS. 



The Pattern Maker and His Trade, .... i 

The Pattern Shop — Its Position, Size, and Requirements, - 5 

Marking and Recording Patterns, 9 

Printing-Press Cylinders, - 14 

Differential Chain Pulleys, 16 

A Handy Tool for Laying Out Hexagon Nuts, - - 19 

How TO CAST Journal Boxes on Frames, - - - - 20 

How to strike an Arc by the aid of Three Points, - 21 
Key-Heads for Motion Rods — The way to lessen the cost of 

their production, -----... 23 
Elbow and Tee Pipes — A quick method for turning the patterns 

aud core-boxes in the Lathe, 25 

Slide Valve Cylinders, ----.-.. 27 
Corliss Cylinders — With a full description, showing how to 

construct patterns and core-boxes which can be changed at 

short notice for different stroke Engines, - . . . 30 

VhY Wheels — Different styles, - - 37 

Engine Frames — How to build the pattern to serve for various 

strokes, . . . . 41 

Spur Gears — How the teeth should be made, - - - . 4^ 

Bevel Gears — The manner of laying them out, - - - - 49 

How to lay out the Thread of a Worm for the Pattern, 52 
Worm Wheels — The way to get the angle of teeth and the 

manner of fastening them on, 54 



CONTENTS. 

Sweeping Straight Winding Drums, 57 

Making Winding Drums from Pat ferns— Method of cutting 

the groove, 59 

Making Sheaves from Core-Boxes, 6i 

Making Sheaves from Patterns, ------ 66 

Sheaves with Wrought Iron Arms — An original way of 

making the Hub, - - - ----- 69 

A Machine for Sweeping Conical Drums— Designed by the 

author, ----- 71 

Items for Pattern Makers, - - 75 

Building up Spur Gear Pinions, . . - - . 79 

Foundry Core-Boxes, -------- 80 

Making Ammonia Pump Cylinders, - . . - 82 

Plug Valves, ----- 83 

Governor Valves, 86 

Double-beat Valves, 89 

Propellers, - - 94 

Gear Teeth — One hundred and Twenty-eight full size different 
profiles of Gear Teeth from \" to 3''^ Pitch, suitable for gears 

having from 14 to 800 teeth, ------ ^3 

M/^king Wheels in Halves, 100 

Table showing at a glance the required diameters of Gear Wheels 

for a given number of teeth and pitch, 106, 107, io§, 109, 1 lo, ill, 112 

Weight of Cast Iron Pipe, - 113,114 

" " Cast Iron Balls, 113 

" " Round Cast Iron, 115 

" " Square " " I15 

" " Flat " " 116 

" " Superficial Foot of Cast Iron from %" to 2" thick 116 

" " Round Lead, - .117 

" " Square "• -...--- 117 

Binary and Decimal Fractions, - ^^7 

Table which gives distances to open a 2 ft. rule for obtaining angles 

from I ° to 90°, 118 

Metric Measure reduced to inches, '^9 



THE PATTERN MAKER AND HIS TRADE. 

For one to be a good pattern maker it is indispensable 
that he should have a theoretical knowledge of mould- 
ing, and be able to read drawings readily — for he must 
know how a pattern is to be moulded, and to mentally 
see the machine, or parts of it, just as the draftsman does 
before he can do much toward making the pattern. 

To become an expert in handling tools is the most 
necessary requirement in many trades, but this is not the 
case in pattern making — there being something far more 
important than cutting wood. 

In very many patterns it is not so much a question of 
workmanship as of knowledge, for there are certain pat- 
terns which, after they are made, may be duplicated by 
any good wood worker, workmanship not having been 
the all-important ; in fact, some very important jobs re- 
quire but very little skill to construct the necessary core- 
boxes, etc., that may be required to produce certain cast- 
ings. On the other hand there is much that calls for fine 
workmanship and less scheming. This is no doubt true, 
more or less, in all trades, but it is especially so in pat- 
tern making, and this is why I say that pattern making is 
not merely cutting wood. From the very nature of the 
trade, a pattern maker is a good worker in wood, because 
he is accustomed to work to finer measurements than the 
ordinary wood worker. 

The pattern maker's position in some establishments 
is an important one, and the responsibility resting upon 



2 PATTERN MAKING. 

the leading man or foreman of that department, as to 
whether work turns out right, is equal to that of the 
drawing room ; for while the draftsman is responsible for 
the design, upon the pattern maker rests a large propor- 
tion of the responsibility of executing correctly that 
which has been put upon paper. 

The liability to mistakes is reduced considerably when 
the machinist takes hold where the pattern maker has 
left off; the machinist's part is no doubt the most impor- 
tant as to the workmanship and right working of the 
machinery ; he can make it good, bad, or indifferent ; but 
mistakes in measurements he is not so liable to as the 
pattern maker, because the machinist has the casting, 
and is given the drawing of it with instructions to finish 
to drawing. 

When a pattern maker is given a drawing, he has to 
imagine the casting before him, and build something 
that will produce it ; it may be called a pattern, but often 
it is really not a pattern of what is wanted, it being all 
core-boxes and no pattern, and here is where the respon- 
sibility comes in, and will, I think, explain why the pat- 
tern shop is often the birth-place of mistakes. 

Of course, mistakes ought not to occur ; but as long 
as pattern makers are fallible, they will happen some- 
times, though the utmost precaution be taken. I am 
always suspicious of the man that never makes mistakes ; 
he will need watching, for the over-confident man is not 
to be trusted any more than those careless pattern makers 
who are constantly making blunders, and who think 
when their patterns come within an eighth of an inch it 
is near enough. 

From the nature of the trade of machinery pattern 



PATTERN MAKING. 3 

making, there is more danger of errors being made in 
that branch of machinery building than others, this being 
so, the careful, industrious workman, who seldom makes 
an error, is worthy of consideration when he does happen 
to be caught, for such a man usually feels bad enough 
over his mistakes, without having the foreman make him 
feel worse. 

Owing to the advance made in mechanical arts, pat- 
tern making is becoming one of the most important 
branches in machinery building. It is often underrated 
by a class of machinists who think that because a pattern 
maker is not called upon to work in iron, and to one- 
hundredth or one-thousandth part of an inch, that there 
is not much in pattern making ; and yet the pattern 
maker is as much of a machinist, in reality, as those 
generally known as such. 

The onward march of improvements in machinery 
demands that the pattern maker must keep right up 
abreast with the times, although he is considered "a 
necessary evil " among manufacturers. 

There is a great deal of machinery now constructed, 
the coring of which is so complicated that it taxes the 
ingenuity of both pattern maker and moulder to know 
how it can be made at all — the winding passages and 
secret chambers that are wanted in some castings, are 
worse than those we read about in books. The old fash- 
ioned idea of bolting on an arm here, and screwing on a 
bracket there, are fast disappearing. The modern plan is 
to make a machine with as few pieces as possible, thus 
making the pattern more difficult to build. 

There are many patterns that require little or no 



4 PATTERX MAKIXG. 

knowledge of pattern making to make, but I would not 
advise anyone, because he has made a few such patterns, 
to pose as a pattern maker ; there are those w-ho do. I 
have had some experience with them, and hope always 
to be delivered from such. They are a worry to any 
foreman — he is in constant fear that wdth all his watch- 
ing, the would-be pattern maker will make some serious 
blunder that will cost the firm a considerable sum of 
money — for a mistake in the pattern means a mistake in 
the casting, and as an old employer of mine used to say: 
*' Cast iron mistakes are rather serious things." 

The fact that there are so many different ways of 
moulding, gives a great field for study for the pattern 
maker, as to the best way of making a pattern ; but when- 
ever a complicated piece of work is to be done, the 
moulder should be consulted, and I do not think that 
the pattern maker will lose any of his ideas by consulting 
with his brother, the moulder, and while the practical 
parts of the two trades are as unlike as possible, yet there 
is a connection between the moulder and the pattern mak- 
er that is inseparable. If discussion is necessary, let it be 
carried on intelligently, each respecting the other's opin- 
ions. Wherever this is done, good is sure to result, and 
the chances are that the best way of doing a job will be 
arrived at. There are those who are so eager to advance 
their own ideas and have them carried out, that they are 
unwilling to consider those of others ; such persons are 
not likely to be very profitable to any concern, for they 
think more of airing their own genius than of arriving at 
any results that might be of practical value. 



PATTERX MAKING. e 

THE pattp:rn shop. 

ITS POSITION, SIZE, AND REQUIREMENTS. 

The question has often occurred to me why pattern 
shops should be located on the upper floor of a building, 
as they usually are, where the foundation — if it may be 
termed such — for fast-running machinery is anything but 
what it should be. It is sometimes risky business turn- 
ing a large pattern in a lathe whose only foundation is 
an upper floor that springs with every motion of the 
machinery, and the chances that pattern makers take 
when turning a large pattern under these conditions are 
great. 

The foundation for large face lathes for turning large 
diameters cannot be too rigid, but I have known the 
trembling of a large face plate to be caused not so much 
by the floor as by having an arbor that was too small, 
or bearings that w^ere set too closely together. 

The inconvenience attending the getting of large pat- 
terns up and down a stairway, or on an elevator, as the 
case may be, is another reason why the ground floor is 
a better location for a pattern shop. 

Plenty of room and light are also essentials generally 
lost sight of. The pattern shop is sometimes called the 
pattern room, and with many firms it has been rightly 
named, having, as is often the case, such a small space 
set apart for that purpose that it has scarcely deserved 
the name of shop. 

The nature of the trade that is carried on, determines, 
in a large measure, the size pattern shop a firm requires. 



5 PATTER X MAKING. 

A firm of large dimensions making specialties does not 
need such a large pattern shop as a smaller one that 
builds engines and general machinery. It is more to 
this latter class of manufactories, employing about twelv^e 
to fourteen pattern makers, that reference is made. 

Enter a number of manufacturing concerns, and in 
nine out of ten, it will be found that the pattern makers 
are working so closely together as to prevent them from 
getting around their work in a proper manner ; and it is 
surprising how a job may be impeded for lack of room 
to build it. 

When it happens that there is a run of large work, 
then it is that the oft repeated expression is heard " We 
ought to have a larger pattern shop." It is true that 
shops are sometimes situated on such valuable property 
that a limited space only can be allotted to each depart- 
ment ; but this does not do away with the fact mentioned. 
In these days of sharp competition, the firms that are not 
cramped for space are the successful competitors in the 
machinery business. 

A pattern shop about 75 ft. x 50 would be a convenient 
size for working the number of men named. 

The machines should not be located all over the shop, 
but at one end within a reasonable working distance of 
each other. 

Among the requirements of such a shop would be a 
face lathe for turning large patterns, 30'' lathe with bed 
about 18 ft. long, 16'' lathe for small work, combination 
circular saw table, plain saw table, with saw about \2" di- 
ameter, band saw, jig saw, surface planer, Daniel's plan- 
er, two or three Fox Trimmers, and about six dozen 
(rather more than less) of assorted clamps. I mention 



Fig- i 




FJiosT nj^u 




BACK VIEW 

C in. STROKE: 5 in. RISE: BED 6 :s. 15 inches: We iyftt 25 Ihs 
For SMALL PATTERN WORK. 

FOX'S TRIMMER. 



PATTERN MAKING. y 

this smaller item of clamps in order to insure a plentiful 
supply. Much time is frequently lost by men waiting 
on each other for clamps. 

The Daniel's Planer is a machine that no pattern shop 
of any pretentions should be without. For surfacing 
stuff for pattern makers this machine has no equal, espe- 
cially when knives are kept sharp, and a good supply 
should always be on hand. 

The Trimmer mentioned is also a very valuable addi- 
tion to the pattern shop, in fact, it has come to be a 
standard tool, and the shop that is without one is away 
behind and had better hurry up and get at least one. 

I believe the success of this machine and its being 
adopted so generally in pattern making, is due to the 
fact that it was invented by a pattern maker who de- 
signed it at the time for pattern making. The Trimmer 
has certainly done away with a great deal of the paring 
that used to done with a chisel, and which was exceed- 
ingly laborious, as most of my readers know, especially 
when cutting end-way of the grain. For building up 
segment work the Trimmer has become almost an indis- 
pensable tool, and will cut as straight and as clean as it is 
possible to cut wood. Figs, i and 2 are two views of the 
smallest size Trimmer made by the Fox Machine Co., 
Grand Rapids, Mich. The illustrations will give the nec- 
essary explanation and will be readily understood. The 
Company make several sizes and the most fastidious 
"wood butcher" can be suited. 

It is not necessary to go into the details of pattern 
shop requirements, but there is a mechanical paper pub- 
lished that ought to be considered a requirement for 



8 PATTERN MAKING. 

pattern makers, and that is the American Machinist. 
Doubtless this is the best and cheapest technical educa- 
tor we have, for it contains more practical ideas for doing 
work in all the branches of the machinery business than 
most papers. 



PATTERN MAKING, 



MARKING AND RECORDING PATTERNS. 

The practice of fixing a mark or symbol on a pat- 
tern to distinguish it fi"om others, is an excellent one, 
and the pattern department of any firm cannot disregard 
it without having much trouble. In many places a large 
stock is accumulated, regardless of any system, because 
the man who looks after them calls it " Red Tape " to 
mark patterns and record them, and boasts of knowing 
where to find any pattern without any such nonsense, 
while at the same time they may be piled together like 
a lot of kindling-wood. What this rule of thumb indi- 
vidual says may be true, about knowing where to find 
any pattern, but who could find the patterns and know 
about each piece if he moved off this mortal coil ? 

The disadvantage that such a firm labors under 
through not adopting some system of marking and re- 
cording is great, and to those who have no system I 
would recommend the following : — 

Fix a raised letter and number on the pattern, so that it 
shall appear in the casting. The letter is to designate the 
class of machinery, or it may be used for a certain ma- 
chine ; the number, to distinguish one part from another. 
The mark that each pattern gets should also be put 
on the drawings. This is not generally done, but I 
think if it were, it would greatly facilitate the work in the 
machine shop. The method which I worked for many 
years is shown by the sample entry of patterns given on 



10 J^ATTERN MAKIXG. 

the follovviiii^ ])ages. The column "pattern at" will he 
found very useful to those sending out their patterns ; it 
is intended to show where the patterns are. In connec- 
tion with this column an index is made showing the 
names of firms with whom business is done. Each firm 
is given a number, as shown ; when a pattern is sent out, 
the number corresponding to the firm it is sent to is 
marked with lead pencil in the column, " pattern at," and 
opposite, the pattern that is sent out ; when it is returned 
the lead pencil mark is rubbed out, showing that it has 
been returned and stored in its place. 

It often happens that in a set of patterns for a certain 
machine, there are those that will do for other machines ; 
in such cases an entry should be made in the sched- 
ule of each machine that this piece will suit, giving the 
same letter and number of the pattern. 

There is always a large number of miscellaneous pat- 
terns that cannot be so well classified, yet many of them 
are often used and need marking ; these may be given a 
symbol and entered under the head of " miscellaneous." 

There are also some rough patterns made, the kind 
that is generally " wanted to be cast to-day." All mould- 
ers are acquainted with this kind. It is no use recording 
such patterns, as they are seldom used the second time ; 
in fact, I think the best way to deal with this class is to 
break them up. 

With large manufacturers carrying patterns for a num- 
ber of different machines and many classes of machinery, 
the question may arise what to do when the alphabet is 
exhausted. When that happens, two letters can be used 
to designate a machine or a class, commencing with AB~ 



PA 'I'TERN MAKING. 



Specimen Entry for Pattern Record Book. 

18 AND 20 Corliss Engines. 



Il 


NAME OF PART. 


^ < 


Weight. 


< 


REMARKS. 




CAST IRON. 










A. I 


Engine Frame 1 8^^ x 36^^ 




3.555 


2 




U 1 


" 18^^x42^^ 




3,905 




This pattern is con- 
structed so that it can 


" I 


'' 18^^ X 48^/ 
" " 20^^ X 36^/ 








easily be changed to 
dififerent strokes and 


" I 


" 20^^ X 42^^ 
" 20^' X 48^^ 








sizes. 


" 2 


Main Pillow Block, - - 


- 


2,015 


3 




" 3 


Cap for Block, - - . - 




475 






" 4 


Oil Cover, - - - - - 




10 






" 5 


Corliss Cyl'der 18^^x36^^ 




3,790 


2 


^ 


" 5 
" 5 
" 6 


" 18^^ X 42^^ 
" 18^^ X 48^^ 
" 20^/ X 36^^ 


I 


4,290 




Patterns are ar- 




4,125 




■ ranged on the tele- 
scopic principle. 


" 6 


" 20ff X 42^^ 




4,280 






" 6 


" 20^^ X 48^^ 








^ 


" 7 


Frame Foot, - - . . 






I 




" 8 
" 8 


Cylinder Feet (20^^ cyl.) 








\ One Pattern. 

\ Loose piece on top 

J for i8/^ 


" 9 


Crank 36^^ stroke, - - 










" lO 


- 42^^ - - - 











12 



PA TTERN MAKING, 



Specimen Entry for Pattern Record Book. 

18' AND 20 Corliss Engines. 





NAME OF PAR*T. 


0^ 


a 


w 


V, 
< 


REMARKS. 


1 


\. 70 

" 71 

' 72 
' 73 
' 74 
' 75 
' 76 
&c. 


BRASS. 

Key Heads, - - - - 
Knock-off Latches, 
Conn. Rod Box, - - 

Bushing for Piston Rod, 
Bonnet Bushings, - - 
Ecc. Strap Shims, - - 


12 

2 

I 
I 
I 

4 
2 






Strong Bronze. 
Crank End. 
Crosshead End. 


A. loo 

" lOI 

&c. 


CAST STEEL. 

Crosshead Nut, - - - 
Cheek Pes. for P. Block, 


I 

2 




6 
6 


Nov. 3d, 1892. 
" 3d, 1892. 



INDEX OF PIEMS TO WHOM PATTEENS AEE SENT. 


I 


Eddy Foundry Co., ... . 


. Chicago, . . Iron Foundry. 


2 


Chicago Foundry Co., . . . 


. . '' 


3 


BouTON Foundry Co., . . . 


« <( u 


4 


Webster Mfg. Co., . . . . 


<< . . " " 


5 


Tarrant & Ramsay, . . . . 


" . . " '* 


6 


Pittsburg Steel Casting Co., . 


. Pittsburg, . Steel " 


7 


Solid Steel Casting Co., . . 


. Alliance, 0., " " 


8 


Eureka Cast Steel Co., . . 


. Chester, Pa., - " 



PATTERN MAKING, I 3 

AC- AD, etc., until through the alphabet again; then 
begin with BC-BD-BE, and so on ; thus, it will be seen 
that it is possible to have a large combination of distinct 
and separate classes without confusion. 

The advantage of recording and marking patterns is 
that it facilitates ordering the castings and helps to pre- 
vent confusion in the foundry. When the order for 
castings is written out (as it always should be) for the 
foundry, the mark corresponding to that on the pattern 
is put on the order so that the moulder and the pattern 
maker cannot misunderstand each other by naming 
things differently. Again, when a pattern has a particu- 
lar mark, every loose piece (and sometimes there are a 
great many) belonging to the pattern, and also the core- 
boxes, can be stamped with a mark corresponding to the 
pattern. The benefit of this is apparent. There is often 
much trouble caused by not knowing where a certain 
loose piece belongs, and castings are frequently made 
minus a piece just because the moulder did not know 
that it belonged to the pattern ; but if eveiy piece is 
marked as I have said, it leaves no excuse for such omis- 
sions. The raised letters that are nailed on the pattern 
help greatly in checking the castings when received. 
Especially is the marking of patterns necessary for this, 
as gentlemen of the quill profession, who generally check 
the goods, are not usually acquainted with the names of 
the parts of machinery. Also by this method the finding 
of patterns is rendered easy even to a stranger; that is if 
,the shelves where patterns are stored are marked with 
the letter corresponding to the class. 

Every firm, large or small, should have some such 
system as I have described. 



14 PATTERN MAKING. 



PRINTING-PRESS CYLINDERS. 

Some printing-press cylinders have the ends bored 
out and a short shaft pressed into each end, while others 
are made with the shaft and cylinder cast in one. Fig. 
3 is a section and end view of the latter. 

A great deal of trouble is often experienced In getting 
perfect castings for these cylinders, and to insure good 
castings they are cast on end in dry sand, or at least they 
should be ; but in spite of all the preventives used against 
blowholes, dirt, etc., a cylinder will sometimes reveal 
defects when the first cut is being taken off in the lathe. 

Though cast on end, the cylinder is moulded on its 
side, so that the pattern is made in halves in the ordinary 
way, as shown in Fig. 4. 

As an extra precaution against defects an additional 
piece five or six inches long is cast on the end, as shown 
in Fig. 3 from a \.o b., the pattern therefore should be 
made that much longer. 

The extra length will receive the impurities of the 
metal which rise to the top when pouring. It is made 
thicker on the ends, so that it shall form a head which 
will exert a pressure, thus helping to produce a clean 
and sound casting. 

Figs. 5, 6, and 7 are three views of the core-box. 
The end \iew, Fig. 5, shows it to be built up with staves, 
which are nailed to three crosspieces, A, B, C. The 



PATTERN JL-iKING. I 5 

box is strengthened by running four strips, c, d, e, f, 
lengthwise on top and bottom of the box, fastening them 
to the crosspieces. 

Two of the arms in each set are let in about yiJ' on 
the inside to keep them from being rammed out of place,' 
but a dowel pin is put in each of the arms that go in the 
bottom of box. 

This is a very plain and simple job in pattern making 
and needs no further comment. 



1 6 FATTERN MAKING, 



DIFFERENTIAL CHAIN PULLEYS. 

When the groove in a chain wheel or pulley is made 
to fit the links of a chain it is sure to be an expensive 
pattern, especially when made double, like those used in 
Weston's Differential Pulley Blocks. 

Figs. 9 and lo are two views of one of this kind of 
pulley. Fig. lo shows a half section and the pockets for 
the chain. Fig. 9 is a section through the groove C, D, 
of the large pulley, which has one more pocket than the 
smaller one. This view also shows how the chain fits 
into the pockets. 

It may not be out of place here to make a few remarks 
about this celebrated Differential Pulley Block that has 
so revolutionized the lifting of heavy weights, and for 
which this kind of pulley was used, in fact, this pulley 
was the main feature of the patent. T. A. Weston was 
in this country when he conceived the idea that led up 
to the Differential Pulley Block. 

While Mr. Weston was at Buffalo, witnessing attempts 
to raise a vessel that had gone down off that city, the 
thought occurred to him that the necessary power could 
be obtained from the Chinese windlass, the rope of which 
winds on two unequal diameters, that is, one half the 
length of the barrel is larger in diameter than the other. 
This is practically what this pulley block is developed 
from. 



Thj. 0. 



rbj. 10. 



> Ftff. 8 




DIFFERENTIAL CHAIN WHEELS. 



PATTERN MAKING, 1/ 

After much scheming, Weston returned to England 
and called on numerous engineering establishments, sub- 
mitting his drawings, but he could find none that would 
take hold and experiment on his block. Finally he called 
into a small job shop where the proprietors themselves 
were working men, paying the extravagant rent of ten 
shillings a week, and employing six men. That firm 
has grown since then and employs as many thousands 
now. I refer to Tangye Bros., Birmingham. 

These brothers labored hard to make the block work, 
and experienced many unexpected difficulties, and when 
they had perfected it and made it a commercial success, 
a new difficulty presented itself in the shape of a law-suit 
in which the Tangyes won. It is pretty hard to conceive 
of any taller swearing than was practised by the would- 
be infringers in this case, but I will return to the pattern 
of the pulley. 

They are sometimes made so that all the links of the 
chain fit into the pockets, but this is an unnecessary 
expense. The links of the chain that set edgewise in 
the pulley do not need to fit into pockets like those 
shown at a, in Fig. 8. If the grooves bb, in Fig. lo, 
be turned deep enough to clear these links and pockets 
made for the other links to set in, it will be sufficient 
to catch the chain, and will work better than otherwise. 

The groove is sometimes formed in a core-box, and a 
print put on the periphery of the pattern, thus making 
fewer partings in the patterns as well as the mould; but a 
much cleaner and better casting can be obtained from a 
pattern with the groove for the chain cut in it. 

Fig. 1 1 is the section of the pattern and shows how it 



I 8 P^ TTERN MAKING. 

is made. The mould is also represented with the cope 
lifted off, the partings being at E, /% G. The pattern is 
built up with segments and made in four parts, c, d, e, f. 
As will be seen, the casting is cored out at A. B., in Fig. 

lO. 

Fig. 12 is a section of the core-box for this core, and 
is parted at H. The core sets into the round prints g. 
g. ; but there are no cope prints, for the reason that it is 
not easy to close the cope over the six round projecting 
cores. In the absence of these cope prints the moulder 
will need to take care that the cope bears on the top of 
these projecting cores enough to prevent the iron from 
running in the vent holes of the core, when pouring. 

This lightening core can be made in halves or whole, 
just as the core-maker chooses. 




I"uj. 13 



Tool for. laying out Hexagon Nuts 



JFig. 14. 



m'i^^m i^e^^^^g^ 



liy. 15. 

Dry Sand Cores^ C 




Ho IV to Cast Boxes on the Sides of Frames. 




Mow to Strike a Curve when the Centre is Inaccessible 
mg. 16. 



PA TTEKN MAKING. 



19 



A HANDY TOOL FOR LAYING OUT 
HEXAGON NUTS. 

Fig. 13 illustrates a tool for laying out hexagon nuts, 
and is very handy to pattern makers ; the section of it is 
shown at A. The upper part, which is a light steel 
blade, is screwed on the lower part, which is made of 
hard wood and is used in the following manner. After 
turning pattern to long diameter of nut, place the tool on 
pattern like a center square, move it round and mark off 
sides — keeping the two under edges in contact with cir- 
cle — this is better and quicker than dividing off with 
compasses and then marking sides. 



20 PATTERN MAKING, 



HOW TO CAST JOURNAL BOXES ON FRAMES. 

The part of a frame shown in Figs. 14 and 15 is one 
of those jobs that at first looks a little troublesome for 
moulding, and yet, upon examination the trouble vanish- 
es. The two views show part of a frame with two boxes 
cast on the sides. The shape of this frame is such as to 
necessitate casting the boxes down ; it will be seen that 
there is not enough room to draw in the boxes, the sides, 
A and B, not being thick enough to allow it. This diffi- 
culty may be overcome by making the pattern as shown. 
The boxes are loose and located on the sides of pattern 
with loose dowel pins that can be pulled out while ram- 
ming up ; two cores are made and dried for the boxes, 
and rammed up with the pattern to C, after which the 
cores are taken out, and the sides of boxes, i, 2, 3 and 
the bracket, 4, are drawn. The cores for boxes are then 
replaced and covered over with sand, the flask rammed 
up and rolled over. There are other ways of making 
this pattern ; a core print might have been put on the 
pattern, as shown by dotted lines, and a core-box made 
with box pattern in it ; but the above way of doing it 
makes a cleaner job. This plan is adopted on many jobs 
where there is not room enough to draw in loose pieces. 



PATTERN MAKING. 



HOW TO STRIKE AN ARC BY THE AID 
OF THREE POINTS. 

It is sometimes required to lay off an arc, the radius of 
which is given ; but the radius may happen to be so 
great as to render it inconvenient to locate a center to 
strike the arc from, or the center may be inaccessible 
from various reasons; under these conditions the ques- 
tion arises what to do to get the arc. 

The following is by no means new, yet it is so little 
understood by pattern makers generally, that I think it 
worth while presenting. The all important, in this prob- 
lem, is to know how to get the point C, or the versed 
sine of arc in Fig. i6; this must be calculated before 
anything can be done towards striking the arc. Let us 
suppose the line ^4 ^ to be , say 4 ft., and to represent 
the chord of an arc whose radius is 20 ft. ; it is required 
to strike this arc without using the center. By using 
the following formula the desired point can be obtained : 
v=rR — ^^R^ — c^. This formula need not scare anyone 
who is not familiar with algebraical expressions; it is 
very simple, let us examine it. v is the versed sine, R, 
the radius, c, the semi-chord, v is what we want to get. 
The formula means that the square of half the chord, 
which is 4 ft., must be deducted from the square of 
the radius, which is 400 ft., this will give 396 ft. ; then 
extract the square root (1) of 396 ft. which is about 



22 PATTERN MAKING. 

19.9.' the formula is now reduced to v==R — 19.9. which 
means that 19.9 must be deducted from R, the radius, 
20 ft., this leaves jV of ^ ioo\.\ J^ ^^ "^ foot is ly^/'-j-which 
is the required versed sine. 

Having obtained the versed sine of this arc, it is an 
easy matter now to strike the arc — it is done by cutting 
a piece of wood to an angle, two sides of which run from 
point C and through A B ; drive a wire nail at each 
point of A and B in the piece on which the arc is to be 
struck. It will be readily seen now, that, keeping the 
sides of angle against A B, and moving it right and left, 
the arc can be traced by following with a lead pencil the 
point C. The principle of this is the same as many pat- 
tern makers are familiar with — that of using a square 
for a templet when working out a half-circle core-box. 




MfO 



Fly. 21. 



By ■ 



m 



P=4/ifcJi! 



f. 



Fig. 30. 





-J 






D 


F 




1 


iil: ■ 







Fig. 



"Of\«« 



o 



KEY HEADS. 



PATTERN MAKJAG, 23 



KEY HEADS FOR MOTION RODS. 

AN EASY WAY TO LESSEN THE COST OF THEIR PRODUCTION. 

The cost of getting out brass key heads for motion 
rods may be considerably reduced in the machine shop 
by the pattern maker doing a little scheming and the 
brass moulder exercising care in moulding. 

Figs. 17 and 18 are two views of a key head, with 
block A in place. A dry piece of cherry or mahogany 
should be selected and the pattern made as shown in 
Figs. 19 and 20; it should be in halves, B C being the 
parting line. D E, Fig. 20, are core prints which carry 
the core horizontally. After the core is located a steel 
key is set in the mould into the print a, the cope print b 
bringing the key upright when cope is being closed. 
The box for the core is shown in Figs. 21 and 22 and is 
doweled together at c d. Fig 2 1 ; a key passes through 
this core-box, which makes a groove in the core to re- 
ceive the steel key. 

It is the intention, when the castings of these heads 
are being fitted up, to file the round ends, while the sides 
are to be finished in the machine, therefore the stock 
allowed for machine finish must stop off at/^. 

There need be no fear of chilling the sides of the holes 
through casting steel keys in these heads ; the effect is 
rather the reverse of what would happen in cast iron, for 
it is well known that if the same thing were to be done 



24 PATTERN MAKING. 

in cast iron, the sides of the holes would be so hard that 
it would be almost impossible to dress them out with a 
file. A number of keys should be made expressly for 
casting into the heads, and they ought to be nicely fin- 
ished, having about ^^' taper sideways ; this will enable 
them to' be easily driven out. 

I have seen much time wasted in the machine shop 
making these key heads, such as drilling and chipping 
out the key hole from the solid, and finishing the round 
end in a shaper. This led me to devise the above sim- 
ple way of casting them, which has proved a great saving. 

When making large quantities of these castings, a 
wood pattern will necessarily get broken and badly 
marked with the moulder's vent wire, so that under such 
circumstances, a metal pattern and core-box would be 
more serviceable. I would therefore propose that the 
standard pattern be made of aluminum and the core-box 
of cast iron. Aluminum is just the metal that is wanted 
for such small patterns, because it possesses the two nec- 
essary and important elements most desirable for pat- 
terns, strength and lightness in weight ; a very nice sur- 
face can also be made on this metal, which is also the 
thing needed. 

Moulders do not like a heavy pattern, for the reason 
that it is not so easily drawn as a light one. 



I 



Fig. ^5. 



Fig. 24. 




Fig. 26 




Fig. 27. 



Fig. 28. 





ELBOWS AND TEE PIPES. 



FAl'TEKJV MAKING. 25 



ELBOW AND TEE PIPES. 

A QUICK METHOD FOR TURNING THE PATTERNS AND 
CORE-BOXES IN THE LATHE. 

Making patterns for elbow and tee pipes, if made the 
right way, is comparatively simple, because nearly all 
the work can be done in the lathe. For turning out 
a large number of castings the elbow pattern should be 
constructed as shown in Fig. 23, so that two elbows 
can be moulded together. A ring is turned like Fig. 24, 
the section of it being a half circle, the same size as the 
pipe ; this ring is cut in quarters as shown, and the four 
pieces used to make quarter turns for the elbows. In 
Fig. 23, the two spicket ends A and B, and the sockets, 
with core prints, are turned on one stick and cut off; the 
stick should be sawed off long enough to permit of 
tongues being turned on A and B, and the sockets, for 
fastening them to the elbows ; dowel pins should be ar- 
ranged to come one in each socket, and in the print 
between A and B, as marked. Fig. 25 represents the 
core-box, and, like the pattern, most of the work can be 
done in the lathe and the parts joined together, as shown; 
a piece screwed on the back will hold the parts to- 
gether. The core is generally made in halves, so that 
a full box will not be needed, and therefore only two 
quarters are used for the turns. In some cases these two 
quarters that are left may be used to turn the socket ends 



26 FATTERX MAKIXG. 

C and D. The dotted lines show that in this case ; the 
pieces left over cannot be used without cutting out the 
corner E and inserting a piece; in a small elbow it would 
not be worth while to do this, but for a larger pattern it 
would probably pay. 

Figs. 26, 2y , and 28 show the manner of making a 
pattern for a tee pipe, and will need but little explana- 
tion, as it is made much in the same way as the elbow, 
all the parts being turned and fitted together. In 
addition to being quartered, the sides of the ring in Fig. 

27 are cut off and the parts joined together at F, Fig. 26. 
The parts for the core-box are also cut this way. Be- 
fore gluing the joint /^together it should be sized with 
glue, after which the joint will be very strong when put 
together ; the socket will also help to hold the pattern 
together at this point. This form of tee is to be preferred 
to the right angle ones, because of its extra strength and 
the gradual merging of the passages into each other, 
which renders the flow of water, etc., easy. 




W''^^'r77M'///^//MA', 







■;;;/^f;/^/WW///M^/MM///777777777/ 



FAff. 3S. 








fm 



|W 



Flft. 33. 



riff. 34 



Fiff. 40. 



Fi{/. 3; 



F 



=tr 




"'(I'^ff 



=i 


^.- - . - - ! 


-^ 




a 




h 





Fig. 43. 



Fiff. 44. 



1 2 3 



fcfj 



J* Vr/. 4.7. 




i^/j/. 42. 7^7 J/. 4•,^ 



SLIDE VALVE CVLLVDERS. 



.PA TTERN MAKING, 



SLIDE VALVE CYLINDERS. 

Slide valve cylinders are made in a great variety of 
forms. I have chosen and represented here a well-known 
type, of which Figs. 30, 31, and 32 are three views. 
Fig. 3 1 is a cross section through the steam chest and 
exhaust port, and Fig. 32 is a section through the steam 
port. 

The way of making the pattern for this cylinder de- 
pends largely upon the size of it ; if the diameter is to 
be, say less than 12" , the body of the cylinder may be 
built up solid, but when above that size it would be bet- 
ter to build the pattern with staves, as shown in Figs. 33 
and 34. But one-half of the pattern is shown, which will 
be all that is needed for explanation. An extra thick- 
ness is glued on each stave large enough for turning the 
body of the cylinder to the required diameter, thus 
allowing the prints and the cylinder to be in one, which 
is far better than fastening on the prints. The flanges are 
made thick enough to turn the fillet on the back of them. 
They should be got out, as shown in Fig. 35 ; this will 
prevent the shrinkage of the wood from affecting the 
flanges to any great extent. 

When the body of the cylinder is built up and turned, 
the steam chest is made and fitted on, as seen in Figs. 36 
and 37. The pieces for the exhaust passage A, and 
those to form a thickness over the ports, are also shown 



28 PATTERN MAKING. 

in place. The fillets at a b, Fig. 36, are cut out of a thick- 
ness that is inserted between the end of the steam chest 
and port pieces ; there is no danger of the fillets coming 
out when made in this way. 

The strips on the steam chest, which give an extra 
thickness of metal for the studs, are loose and put on 
with long dowel pins, so that they can be drawn separ- 
ately, also the valve stem stuffing box, r, and the facing, 
d, around the steam opening are loose. The strips are 
shown at r, Fig 37, let in about {^" around the sides of 
the steam chest; this is done to prevent them being 
rammed out of place after the dowel pins have been taken 
out. The core print / should be doweled* on, because 
if it is made fast it is very probable that the moulder 
will tear it off, for it is a great convenience for him to 
have this print to place back in the bottom of his mould 
while dressing it up. 

Figs. 38, 39 and 40 represent the core-box for the 
steam port. Fig. 38 is a side view with the side A 
taken away. The core is swept off on the outside for 
the length of x, but the piece c is made to finish the out- 
side, because the core changes from a circular into a 
a straight part, just where it is entering the steam chest. 
Fig. 39 is an end view of this box, with the end B, in 
Fig. 38, taken away. Fig. 40 is a plan view and will be 
understood from Figs. 38 and 39. 

The exhaust port core-box is made in halves ; one-half 
is shown in Figs. 41 and 42 ; the other half is, of course, 
like this, except that it is made the opposite hand, so 
that the two halves shall fit when put together. The 
dotted line in the end view, in Fig. 42, shows how the 



PA TTERN MAKING, 



29 



passage is widened to maintain the same area through- 
out ; that is, it is cut down along the part in the direction 
of arrow in Fig. 41. 

The steam chest core-box is made as seen in Figs, 43, 
44, and 45 ; the side and end are taken off in Figs. 43 
and 44, to show the inside ; the piece D that forms the 
valve face is screwed on the bottom, and the sides fit 
over it; this core is the first that is set in the mould, 
then the exhaust and steam port cores are set into i, 2, 
and 3, Fig. 45. 



30 PATTERN MAKING. 



CORLISS CYLINDERS. 

SHOWING HOW TO CONSTRUCT PATTERNS AND CORE-BOXES 

WHICH CAN BE CHANGED AT SHORT NOTICE 

FOR DIFFERENT STROKE ENGINES. 

It is often required in shops building engines that a 
cyHnder pattern be so constructed that it will serve for 
engines of different strokes. To illustrate one way of 
making a pattern like this I have chosen a Corliss Cylin- 
der. Fig. 46 shows the wrist plate side and half section 
of cylinder. Fig. 47 is a section through A B, and Fig. 
48 is a section through A' B' . As both halves of pat- 
tern are almost alike, it will only be necessary to deal 
with one half. 

Experience has taught me that ^^" to the foot is 
enough to allow for shrinkage on a job of this kind. 
Use first quality dry lumber ; it will pay to take some 
pains in selecting stuff for this pattern ; for, if the lumber 
is not thoroughly dry, before the pattern is completed, it 
will be found that dimensions are scant. 

By referring to Fig 49, it will be seen, that to make a 
pattern for different stroke engines, I have arranged it to 
slide like a telescope. Fig. 49 is shown pulled apart, and 
illustrates how the pattern is built. Fig. 50 is a section 
of Fig. 49 through C D ; the lagging a b c d e,m Fig. 
50, is taken off in Fig. 49 to facilitate explanation. An 



Fiy. r>o 




I'iy. 67 



Fig. 66. -^ 



^ 



rii/64. 



CCRLISS CYLINDERS. 



section thro' A.b! ViV' ^7 




Fig. 48, Section thru' A.B. 

Dowell Plates 

Section thro' CD. 

8 



Cross 
Pieces 



U h \ 






Flange 



. Fig. SO. 



Fig. 54 




Sliding End 7 D Fast End 7 

Fig. 49. 
Fig. 53. 




Fig. 52. 



Fig. 51. 

CORLISS CYLINDERS. 



PArrEKN MAKING. 



31 



inner box is first made, the length, width, and depth of/ 
g h in Figs. 49 and 50, and doweled together with iron 
dowel plates like sketch. Build out each side of this in- 
ner box for about two-fifths of its length to width G, in 
Fig. 46, then fasten on strongly three cross pieces num- 
bered I, 2, 3. For future reference I will name this the 
" Fast End." 

In Figs. 49 and 50, the outside piece marked 7 should 
be made wide enough for the exhaust passage in Fig. 47. 
Notice that in making the inner core-box the board K is 
cut in two so that one piece may form a part of the slid- 
ing end. On the sides of box, glue and screw two 
guides marked E Fin Figs. 49 and 50; on each side of 
these guides, fit pieces that shall slide over them, and se- 
cure them to the two outside pieces, 7 and 8. This will 
make the sliding end the same width as fast end. Now 
fasten the cross pieces, 4, 5,6, and piece K, to the two 
slides, and be careful not to get any of them glued to the 
box ; the lagging a b c d e,m Fig. 50 will hold this 
sliding end together, and, as the pattern progresses, other 
parts will make it secure. The piece i forms the core 
print for coring out the space T, that separates exhaust 
passage from body of cylinder. (See Figs. 46 and 47). 

In Fig. 49 we have now a foundation to build on, and 
have made it the width of G in Fig. 46. At this stage, 
the length of the pattern, when closed for the shortest 
cylinder required, should be the length of the cylinder, 
minus the thickness of two flanges and \\" for fillets on 
back of flanges. Fig. 5 i represents the pattern closed, 
with a filling piece, //, put into it and the framework of 
Fig. 49 all closed up. 



32 PATTERN MAKING. 

Proceed next to get out the end flanges, valve cham- 
bers, port pieces, etc., and build on. Get out the flanges, 
as shown in Fig. 52, glue on three pieces, /, /, /, ^" 
thick ; this f thickness is for carving the fillets on 
backs of flanges, and makes by far the best job. It must 
be remembered that the cylinder illustrated here is sup- 
posed to be a standard pattern, from which a large num- 
ber of castings may be taken, so that in this case the 
best way will be the cheapest in the end. 

Glue and screw on the end flanges, shown in Fig. 52, 
and the side pieces, a' b' c' d' , Fig. 51, for the valve 
chambers. Build some blocks together, same shape as 
shown in Fig. 53, and fasten them in place at J J, to 
form the ends for steam valve chambers. For very large 
cylinders these pieces had better be boxed. For the 
ends of exhaust valve chambers, L Z, make plain square 
blocks ; now make the exhaust passages the right height, 
by gluing on piece 9 in Figs. 5 i and 54 ; after this, fit in 
the pieces 10, 11, 12, 13, Fig. 51, that give a thickness 
of metal over the steam and exhaust ports. All is now 
ready for rounding off the corners and side of steam 
passage, and cutting the fillets. 

Check down the two inner edges on ends of valve 
chambers (See Fig. 46). This is to allow the bonnets 
to lap over and cover the joint of the black walnut lag- 
ging, that these cylinders are generally cased in. I have 
said that both halves of pattern were almost alike ; the 
difference between them is, the center piece for bolting 
the wrist plate to is usually on the opposite side of the 
small bosses that take the indicator pipe ; also the valve 
chambers are made about one inch longer on the cope 



FAirERN MAKING. ^^ 

side of the pattei n than on the drag side ; this is done to 
insure soHd ends after this extra inch is planed off the 
casting. 

When casting these cyHnders, all dirt and flux that is 
in the mould and metal rise to those four high places 
and stick there ; hence, the necessity of extra stock on 
the ends of valve chambers. 

In turning the eight round core prints for the valve 
chambers make those in the cope as much shorter than 
those in the drag, as the extra stock just mentioned; in 
other words, the core prints should measure the same 
length from the joint of pattern on both halves. The 
necessity of this will be seen when we come to make the 
core-boxes. Give these prints plenty of taper, because it 
will help the moulder to ieel his way when dropping in 
the cores of valve chambers ; it will also help to bring 
the cores upright when dropping on the cope. 

Now fit on the pieces x and 5, to take the exhaust and 
steam flanges (see Fig. 46), and, as these pieces are to 
be removed for sliding the pattern out and in, they must 
only be doweled and screwed on. Screw the core prints 
on these pieces from the back. The center piece, /, Fig. 
46, should only be doweled on. Build up the core prints 
for bore of cylinder, as shown, and turn a flat flUet on 
them at y, Fig. 5 i . This will prevent crushing the edge 
of sand when putting the core in and dropping on the 
cope. Turn these prints whole and saw in halves with 
band saw after turning them ; for large cylinders it will 
be better to build these prints with staves. We may now 
consider the pattern finished. 

There are many details which are omitted, because 



34 PATTERN MAKING. 

they are such as the pattern maker will naturally run 
against ; so let us leave the pattern and start in on the 
core-boxes for the steam and exhaust passages, valve 
chambers, etc. 

It will scarcely be necessary to enter into the minor 
details of making the core-boxes, seeing that I have 
shown both cores and core-boxes for the steam and ex- 
haust sides of a cylinder. 

However, a few explanations may be necessary. Like 
the cylinder pattern, I have only shown half sections of 
cores; Figs. 55, 56, 57, are three views of the core for 
steam passage and valve chambers. A half core-box is 
all that is needed to make this core, the joint of it being 
on line C D' , and the joint of core-box on line E' P. 

Figs. 58, 59, and 60 are three views of the core for 
exhaust passage and valve chambers, also made with a 
half core-box. 

The core-box for the steam core is constructed as 
shown in Figs. 61 and 62. The port cores, e' f ,m Fig. 
57, are made separate, and pasted in ; the core prints to 
receive these port cores are seen at e' f in Fig. 62. 
Like the pattern, these boxes are made so that the length 
can be changed. In Fig. 62 the joint, g' , for the length 
of h' , is not glued, there being a tongue or guide for this 
surface to slide in ; the piece, i, is loose, which can be 
taken out, thus allowing the valve chamber part to be 
slipped toward the center as may be required ; on the 
inlet side of this box, the joint m, for the length of 0, 
and the joint ;/, for the length of/, is also made to slide, 
and when the box is to be shortened, the two pieces, r 
and s, are taken out, which will allow the valve cham- 



PATTERN MAKING. 35 

bers to be slipped toward the center ; each side of the 
inlet is alike. The reason there are more loose pieces on 
this side of the core-box than the other, is because the 
inlet must always be located midway between the two 
valve chambers. 

The exhaust core-box of which Figs. 63, 64, 65, 66 
and 6y are five views, is made open on one side between 
the valve chambers, and as this open side is a plain 
straight surface, it can be swept off with a sweep, as 
shown in Fig. 67. The valve chambers are round, all 
the way through, in this core, as will be seen by referring 
to Fig. 58. Like the core-box for the steam side, two 
pieces, v, w, Figs. 63, 64, are inserted, for changing the 
length. Fig. 6y shows a section of the box; the side x, 
is carried above the center line of valve chambers. 

Fig, 60 shows the side of core runs over the center 
line G, H, hence the necessity of carrying one side of the 
box above the center of valve chambers. 

Figs. 65, 66, are two views of the port halves of valve 
chambers, and, like the steam core, the port cores are 
made separate and pasted in. 

The core-boxes for the exhaust and steam ports are 
made like Fig. 68, except that the exhaust port box is 
made thicker than the steam port box. In small size 
Corliss Cylinders, whole core-boxes are sometimes made, 
instead of half-core boxes, but for large cylinders, the 
cores are better made in halves both for convenience of 
making and drying. 

The box for coring out the space that separates the 
body of cylinder from the exhaust passage may be made 
as shown in Figs. 69 and 70. Make the box half the 



36 PATTERN MAKING, 

length of the space. (See Figs. 46 and 47 at 7"). It 
will be seen that in the center of this space, there is a 
bridge ; to form this, a loose piece, V, Fig. 69, half the 
thickness of the bridge, is made and fitted in the end of 
core-box, and as there must be two right and two left 
hand cores, changing this loose piece to the opposite end 
will give it. It will be found that two other small cores 
are needed, one right-hand emd one left-hand, to core out 
between the valv^e chambers and cylinder on the exhaust 
side. These small cores are really a part of the core for 
coring out the space 7", in Figs. 46 and 47, and might be 
made in one core, like the core print shown in Fig. 51, 
but I think it is easier to make them separately. I have 
not shown these small boxes, as they will be readily un- 
derstood without. 

Those who make Corliss Cylinders, will no doubt see 
the advantage of making their patterns to slide the way 
I have shown, as the pattern can be easily and quickly 
changed for different lengths without damaging it. 



"Fig. 72. 




^ J if/. SO. 

FLY WHEELS. 



Fig. 81, 



PATTERN MAKING. 37 



FLY WHEELS. 

DIFFERENT STYLES. 

Making fly wheels is such an every-day occurrence, 
that it seems almost unnecessary to say anything about 
it, and yet I think something might be said that might 
be of service to some one. 

These wheels are generally cast in halves and bolted 
together, except in the case of a fly wheel with square 
rim, in which case it is generally held together with 
wrought iron links, shrunk on each side of the rim, 
as shown at B, in Fig. 7 1 , or sometimes with cotter-bolts, 
as seen in Fig. 72. 

Fig. 71 is part of a square rim fly wheel, and Fig. 73, 
that of a band wheel. These two wheels are the same 
diameter and of about the same weight. Let it be sup- 
posed each is designed for one size engine ; one cus- 
tomer will want a band wheel for his engine and another 
,may want a fly wheel with square rim, and because of 
this, it is proposed to make the same arm core-box, with 
changes, do for both wheels. Fig. 74 is a section of a 
mould for a square rim wheel ; it will be seen that the 
lower and outside part of the mould are formed in green 
sand, the segment pattern in Fig. 75 being used for that 
purpose. A step is made in this segment at A, so that 
in ramming up, the green sand can be swept off* level 



T^S PATTERN MAKIXG. 

with it ; this makes a level surface on the inside, on 
which to set the cope cores shown in Fig. 74. A pin is 
put through the end that fits over the spindle to prevent 
it from getting away. 

Fig. 76 is a section of the mould for the band wheel ; 
the inside of the rim is all rammed up in green sand, us- 
ing segment in Fig. 77. Two views of the core box for 
the cope of square rim fly wheels are shown in Figs. 78 
and 79, and the length of the box is from B to C, in 
Fig. 71. Z^, in Fig. y^, is a print to receive the core for 
the link, and as there are to be two right and two left 
hand cores, it must be changed to the other end of the 
box for opposite hand cores. Two views of the core-box 
to form the recesses for links are shown between the 
arms of Fig. 71, and cores made in this box will be set 
in print D and also in a print on the segment. 

The arm core-box, of which Figs. 80 and 8 1 are two 
views, should be made very strong, as it, of necessity, 
gets very rough usage. If this arm box is built the way 
I have shown, and a bolt put at each end to hold the 
sides together, it will stand a considerable amount of 
rough handling before coming apart. The depth of the 
box is governed by the distance of the bolt holes in the 
hub from the center of arm ; in this case a, b, in Fig. 82, 
is the depth ; notice also the box is made longer than it 
is needed for these wheels. This is done that it may be 
used for larger wheels. F, in Fig. 80, is made loose and 
is laid on top of E, which is also loose ; the piece, F, is 
used in the box for the lower half of arm cores, and 
for the upper half it is taken out, because the ends of 
the upper arm cores must lap over the outer edge of 



PATTERN MAKING. 39 

mould in the same manner as the cope cores for the 
rim. (See Fig. 74). 

For the band wheel, E and F are taken out and the 
piece in Fig. 83 substituted. The end of the box is then 
made to fit the inside of the rim for band wheel. The 
length from center of hub to C, in Fig. 73, corresponds 
with the distance from the center to dotted lines, d, e, in 
Fig. 71. The three pieces marked i, 2, 3, are used to 
form the hub in arm core-box. In Fig. 80, / is a half 
round core print and is changed to the opposite side 
when piece numbered 3 is used, and on a wheel having 
six arms there will be twelve cores, four of each from 
the pieces i, 2, 3. In order that the cope cores for the 
rim may fit against the sides of arm cores, two wedge 
pieces, g, g, are fitted against the sides of the box, mak- 
ing that part of the box radial, like the ends of the box 
in Fig. jZ are made. In making the core-boxes, a clear- 
ance, (say ^^" on a side) should be allowed where the 
cores fit together at the hub and rim ; nine times out of 
ten the moulder has to file these cores to get them in 
position, and it is very provoking to find, when the last 
arm core is being set, that it will not go in place by \" 
or more. 

The box, in Figs. 84 and 85, is to complete the outer 
part of the hub on each side of line a' b' in Fig. 82. h 
h are half round prints that will match /, in Fig. 80, 
when cores are set. 

In Fig. 74, the dotted line, M, represents the surface 
of a level bed that is struck, and which is the first 
thing to be done towards making the mould, but before 
the rim can be made, the core for the end of hub must be 



40 



PATTERN MAKING. 



located, the top of it being set flush with the bed, M. 
This core, which forms part of the hub, will be a guide 
to set the lower halves of arm cores, which is the next 
thing to be done. After this, the green sand part of the 
mould is rammed up. 

The band wheel is made in much the same manner, 
except that in Fig. 76, the level bed is struck off at N 
and the arm cores blocked up to the proper height, and 
the inside of the rim rammed up. 

The outside of the band wheel can be formed by cores, 
like P, being set around. When making the segment, 
it should be made deeper from the center rib to N, than 
it is to the cope edge. The reason for this is to allow 
for the piece x^ that is made on the core, P, x being a 
guide for setting these outer cores, so as to give the 
desired thickness to rim. 



Fig. 86, 




ENGINE FRAMES. 



PATTERN MAKING. 41 



ENGINE FRAMES. 

HOW TO BUILD THE PATTERN TO SERVE FOR VARIOUS 
GTROKES. 

The type of frame shown in Figs. 86 and '^J is the 
same as used on the Corliss Engines built by the M. C. 
Bullock M'f'g. Co. Chicago, and is considered by 
mechanical engineers to be a strong frame. Among a 
number of ways, it may be difficult to decide which is the 
best way to construct the pattern for both pattern maker 
and moulder, for in all such jobs the pattern making and 
moulding should be considered together. 

Figs. %6, 87 and '^'^ are three views of this frame to be 
built. Fig. 87 is shown in part section towards the 
cylinder end of frame and Fig. 88 is a cross-section 
showing the two ribs on the back. The pattern is to be 
parted on line AB, Fig. 86, and to mould with the two 
ribs down. That part from AB to a, can be lifted with 
the cope, or it can be lifted out with an anchor plate and 
set in on chaplets. This pattern is also made on the 
same principle as the Corliss Cylinder, viz., to slide. By 
doing this, different stroke engines can be made with the 
same pattern. Provision for this change must be made 
between the points CD and DE, in Fig. ^j ^ but the part 
between CD will only be made to slide, while the length 
DE can be changed by making a false end to be used 
for stopping off to the length required. 



42 PATTERN MAKING. 

We start the pattern by building up two half round 
pieces, one to be larger in diameter than the other ; the 
smaller will be the diameter of the inside of frame, and 
will therefore serve as a core print, and the larger for the 
outer diameter of frame. The end view of these two 
parts is shown in Fig. 89, their length is from b to c, in 
Fig. 90. Notice that on one end of the larger part, it is 
turned down to the same diameter as the small part ; this 
is for the sliding end to slide on. 

Get the staves out for building the larger part, and 
glue on an extra thickness, forming a step as shown 
in Fig. 91. After building the two parts, then put them 
together and turn, but as one part is larger than the 
other, they must be balanced before turning. It will be 
seen that only the large piece and the end of the smaller 
can be turned ; the remainder of the smaller piece will 
have to be planed off. Next get some staves out like 
Fig. 92 to make the sliding end H, as shown in Fig. 90. 
The length of this will be from d to e. The flange is 
glued up in two courses and fastened around this sliding 
end, H. The end piece that receives the cylinder should 
not be fastened on permanently, as one frame does for 
two or more sizes of cylinders, so that instead of putting 
on and taking off a lining, it is better to niake two or 
or three ends for changing. 

In Fig. 90 the pattern is shown arranged for the long- 
est stroke. F is a piece bolted on the end at b to give 
more bearing to the sliding end, H. G is a filling piece 
built up in three courses so that whenever it is necessary 
to shorten the frame, these two pieces, F and G, can be 
easily taken out, and the sliding end moved up and 



PATTERN MAKING. 43 

screwed again. By referring to Fig. 86 it will be seen 
that the half of this sliding end that goes around the 
print has to be cut out circular, like the front end in Fig. 
87, and moulding fitted around it. In making the mould- 
ing that is shown around the edge of frame it should be 
made loose from the print as far as <?, 0, thus making 
strong loose pieces, which are less likely to be broken. 

That part of the frame that covers the print should 
now be fitted on. Having the round part of frame ready, 
get the ribs built on the back by first planing two flat 
places on the pattern where these ribs connect to the 
body, wide enough to take a piece that shall form the 
inner and outer fillets at bottom of ribs ; see/. Fig. 89. 

Fig. 93 shows the large part of pattern ; it is laid on a 
plank that is surfaced ; on this plank a center line is 
struck as a guide for getting the other part of frame in 
line with the body ; after locating the center line on pat- 
tern to that on the plank, fix a temporary piece, K, on the 
end, and also a piece, Z, the same height. The point, M, 
shows the full length of frame ; these two pieces, K and 
Z, are temporary supports for locating the straight part 
of frame. On these supports square up a center line 
from the plank. The straight part, N, should be flush 
with the two pieces, f J, in Fig. 89, so that the two ribs 
can have a straight bearing from end to end. 

Now is the best time to bore some holes through the 
body of pattern for screwing on the ribs. It will 
strengthen the pattern to glue some dowel pins through 
the body and down into the ribs. Having put this part 
together securely, proceed to fit in the bracket at P, Fig. 
86, remembering that the inside of these brackets should 



44 PATTERN MAKING. 

match the inside of frame. The two lightening holes at 
the back, seen in Fig. 87, are cored. These cores will 
serve to set the main core on. 

Having completed the pattern, make a half skeleton 
core-box for the inside of frame. This box is seen in 
Fig. 94, of which Fig. 95 is a cross-section. First build 
an end as shown at Q, and though but one-half be 
needed, it will pay to build a full circle and turn it. After 
cutting it in halves, take one and screw on three pieces, 
R, 5, T. To R and 5 screw on two other pieces, U and 
Vy for the guides. When the core is being made, the 
screws shown are taken out, thus leaving £/and F behind 
to be drawn out separately. This skeleton box is 
arranged for the longest, and when changing length of 
frame all the change that the core-box will require is to 
fit a piece in the plain end to the desired length. 



-^■-H^'^rl^^i -,.,<;' 




Tifj.OS. 



SPUR GEARS. 



-- --'-Tf^- 



PATTERN MAKING. 45 



SPUR GEARS. 

AND HOW THE TEETH SHOULD BE MADE. 

There are so many ways of making gear patterns that 
it would be extraordinary to show some new way. The 
question is, which is the best way to make a gear pattern 
that will stand a reasonable amount of hammering, not 
be unnecessarily expensive, and so that a casting when 
taken from it will run smoothly. Even on a gear pat- 
tern much unnecessary time may be spent, and is spent, 
that does not make the pattern any better, but only more 
expensive. For instance, dovetailing the teeth on gears 
\\" pitch and above, is unnecessary work. Much time 
can be saved by fastening the teeth on, as shown in Fig. 
96. I have found this way to be cheaper and by no 
means inferior to dovetailing. 

It is often found that after the rim has been turned 
and the teeth dovetailed on, that the wheel runs out; 
there is no doubt that the cutting of the rim and driving 
in the dovetails have to do with this, and yet there are 
men who will argue that a gear cannot be made right 
unless the teeth are dovetailed on. 

By the method shown in Fig. 96, we have the advan- 
tage of getting a fillet at the root of the tooth, w^hich 
cannot be well made on one that is dovetailed on ; in this 
way the tooth is also strengthened and made better for 
moulding, which means a better casting. 

In making the pattern, the blocks for the teeth should 



46 



PATTERN MAKING. 



be sawed out first, and then the segments for building 
the rim. These should be laid aside for awhile to allow 
any moisture that is in the wood to dry out, and though 
the stock may be considered ever so dry, it is better to 
do this, and the importance of it cannot be over-esti- 
mated in gear making. 

In the meantime get out the arms and put them to- 
gether ; if the arms are of an oval section, now is the 
time to shape them, because it is far easier to do this 
before fixing them in the wheel. 

Fig. 97 represents the way the arms may be put to- 
gether. It will be seen that tongues are inserted in the 
joints where the arms come together. The grain of 
these tongues should not run parallel with these joints, 
but across. 

Before building on the last two courses of segments 
for the rim, turn the rib that is on the inside (see Fig. 98), 
then build the arms in place, taking care not to fit them 
so tightly as to spring the rim — the remaining courses 
may now be laid up. 

In Fig. 98 I have shown a cast iron flanged bushing ; 
the center of arms is turned out to receive it, and is se- 
cured by one or more screws in each arm. I would 
suggest here that it would be a good thing to have a 
bushing of this kind in nearly all wheels, and that a stan- 
dard sized hole be adopted. All hubs should then have 
a projection turned on them to fit the standard size. 
There would be but little trouble then in changing the 
hubs. 

After turning the rim for the wheel, fit on the blocks 
for teeth, and screw them on from the inside of rim ; then 



PATTERN MAKING. 47 

fit strips between, as shown ; take care not to allow any 
glue to get between the blocks and strips when nailing 
and gluing on the latter, because the blocks have to be 
taken off again to work the teeth out. 

In some cases it may be better to screw on a block 
and fit a strip the right width against the side of block 
before screwing on the next one, but this is purely a 
matter of choice with the pattern maker. 

There is quite a variety of systems employed for lay- 
ing out the profile of gear teeth, and I do not propose to 
enter into any discussion regarding the merits of these 
different systems; but much of the controversy is so 
hair-splitting that in practice it amounts to nothing when 
applied to cast gears. In some shops the teeth are laid 
out to " suit the eye." Of course this is entirely wrong, 
and, though such gears may run, there will be much 
jarring and friction, which means extra wear and tear, 
and loss of power. 

For general purposes it is desirable to get that form 
of tooth that shall work with the least possible friction, 
and at the same time be interchangeable with any other 
of the same pitch. There are various ways of getting 
this. One good way is by the use of Prof. Robinson's 
Templet Odontograph. Fig. 96 shows how to apply the 
Odontograph. The full lines show it in position for 
marking the face of tooth, while the dotted lines show it 
reversed for marking the root. 

To locate the Odontograph in proper position for the 
face of tooth, " setting " tables are supplied with the 
instrument, which will give the graduation on the Odon- 
tograph to set to pitch line ; but this graduation is not 



^8 PATTERN MAKING. 

all that is needed to set the instrument by. In Fig. 96, 
two dotted lines, c and d, are drawn from the center of 
the tooth, forming a right angle, d being radial ; now, by 
setting the hollow edge of the Odontograph even with 
the line c, and using the graduation referred to. the loca- 
tion is determined for the face of tooth. 

For the flank or root, two lines, a and b, are drawn 
from the side of the tooth, also forming a right angle, b 
being radial ; by the aid of the line a and the " setting " 
for the flank, the Odontograph may now be set for the 

flank. 

When a setting is found for one part of a tooth, the 

instrument should be screwed on a radius rod, which is 
moved around a center pin in the hub, so that in this 
Odontograph we have a ready-made templet for the teeth, 
and are not troubled with getting centers for the points 
of compasses somewhere outside the wheel or between 
the teeth, as sometimes happens. 

While it is very desirable to make gears that are inter- 
changeable, and which are good enough for all ordinary 
machinery, it must be acknowledged that the best form 
of tooth cannot be made by any interchangeable system ; 
of course, I am speaking now of the epicycloidal form of 
tooth. For some special machinery, where it is neces- 
sary to have the best form of teeth, without regard to 
their being interchangeable, the Odontograph is set 
differently from that for the interchangeable. Prof. 
Robinson gives extra tables for this purpose, and herein 
lies the value of the Templet Odontograph, and I would 
recommend its being used, especially for coarse pitches. 




BEVEL GEARS. 



PATTERN MAKING. 49 



BEVEL GEARS. 

THE MANNER OF LAYING THEM OUT. 

Before saying anything about the construction of these 
patterns, some explanation should be made about the 
Hnes that are required. 

Fig. 99 is a section of the gear and pinion to be' made, 
and gives the angle at which the two shafts are set. 
Fig. 100 is a face view of the gear. Bevel gears are 
usually made to run at right angles to each other, but 
when occasion requires, they can be made to run at any 
aHgle. In Fig. 99, a is the angle that is chosen ; the two 
lines representing this angle are the first to be drawn, for 
on these all the others depend. 

Having the angle, the next to be determined are the 
proportion and sizes of gear and pinion. In this case, I 
have made the proportion about 3 to i, pitch 1^2." - 
The gear is 26.8''' diameter, having 56 teeth, the pinion 
9.1 1 '^ diameter, with 19 teeth. The pmion is made with 
an odd number of teeth, so that the teeth shall not work 
into the same ones of the gear at every revolution, but 
shall be constantly changing ; the odd tooth is sometimes 
called a " hunting tooth." 

The angle and the dimensions being settled, proceed 
by drawing the line b, at right angles to c. This line b 
is the diameter and the pitch line of the gear. From 
point d lay off e at right angles to /; this will be the 



50 PATTERN MAKING. 

pitch line and diameter of the pinion. Draw the center 
line, g, parallel to /; this locates the center, h, towards 
which all the teeth must converge. Draw /, 7", k, the 
center lines of teeth, to h ; on these lines lay off the face 
of the wheels, making the ends of teeth square with the 
center lines, 2,7, k. 

The section of the rim, arms, and hub, are now easily 
drawn. The teeth are laid out on larger circles than the 
diameters of wheels, the centers being A and B. These 
centers are obtained by producing the line representing 
the ends of teeth, or, in other words, making m at right 
angles toy, until it cuts the center lines of gear and pin- 
ion at A and B. The profile of the teeth must be made 
as if the centers of the gear and pinion were at A and B. 
To get the correct thickness of the tooth on the inside, 
the outer thickness must be laid down at ;/, running the 
sides toward the center, h. The profile of the inside of 
teeth is made after the same manner as the outside. 
Having described the method of drawing out these 
gears, we can pass to the construction of the patterns. 

The rim is built up on a face-plate in a manner shown 
in Fig. 10 1, and when the work is thoroughly dry, the 
inside should be turned, getting in around at P as far as 
possible. The arms are fitted in the wheel as shown in 
Fig. 102, which should be done before taking the rim off 
the face-plate. There is a thickness of about y^" put on 
each side of the arms to hold them together, also answer- 
ing for fillets ; see Fig. 103. Tongues should be inserted 
at the joints where the arms join at the center, thus 
making, with the pieces on either side, a strong job. It 
is the intention to leave the hub and ribs, DD, in Fig. 



PATTERX MAKING. 5 I 

99, loose, so that they can be lifted with the cope, thus 
preventing the mould from tearing down. After fitting 
in the arms, the rim is chucked, as seen in Fig. 104, and 
finished on the outside ready for putting on the teeth. I 
have already described the manner in which gear teeth 
are put on spur gears, and these should be put on in a 
similar way. 

Pinions may be built up hollow or solid ; in this case 
it is not large enough to build hollow, so pieces must be 
glued together with the grain of the wood running with 
the axis of pinion, and large enough to allow the teeth 
to be cut out of same. For larger pinions, the pieces 
can be glued around the periphery, the grain of wood 
running the same way as the teeth, then turned off, and 
the teeth cut as if cutting them from the solid, as before. 



52 



PATTERN MAKING. 



HOW TO LAY OUT THE THREAD OF A WORM 
FOR THE PATTERN. 

Let us suppose the pattern for a worm is to be made 
^' diameter, with a single right-hand thread i y^" pitch. 

First, turn the pattern — which should be in halves — 
to the diameter, \'\ and to the required length, say 6'', 
see Fig. io6. Do not destroy the centers, because after 
the threads are cut, the pattern can be returned to the 
lathe, and the threads sand-papered on a slow speed ; a 
much better job can be done at sand-papering this way 
than otherwise. After turning the pattern, wrap a piece 
of paper around it and cut to the exact length of circum- 
ference, and also the length of pattern. After doing this, 
take the paper off and lay it flat, as shown in Fig. 105. 

The full lines which are laid off parallel to each other, 
and \y^" apart, represent the center line of thread, or 
pitch. After making these lines, take the paper and 
wrap it around the pattern again, and it will be found 
that the end marked i will meet the end marked 2, and 
4 will meet 3, and 5 will meet 6, and so on, thus making 
one continuous line when wrapped on the pattern ; but 
before gluing the paper to the pattern, mark the thick- 
ness of the thread. Be careful when you have a right- 
hand worm to make, that you do not make it left-hand 
by running the lines the wrong way; I have seen this 
done more than once. If it is to be a right-hand thread. 



PATTERN MAKING. 53 

the lines should run down towards the left-hand, as seen 
in Fig. 105. If it is to be a left-hand, they should run 
down towards the right. 

When a double thread is required, instead of starting 
to draw the lines from the first division to the corner, 
start from the second, as shown by dotted lines. This 
will give a double thread, and, in fact, any number of 
threads can be obtained this way. If the angle of the 
thread is increased twice, two threads are the result ; if 
three times, three threads, and so on until the number of 
threads are so many, and the angle so great, that we 
cease to call it a worm and begin to name it a spiral 
gear. 

It will probably occur to some minds that if glue be 
used to fasten this paper to the pattern, the moisture of 
the glue will stretch it, so as to make the ends that meet 
lap over ; this can be avoided and the ends need not be 
allowed to lap over, if a little care is exercised. Instead 
of spreading the glue over all the surface of the paper, 
put a little on the two ends that join, and also here and 
there on the surface ; then lay the paper flat and roll the 
pattern carefully on it, the pattern gathering up the 
paper around it as it is rolled. If a spiral gear is to be 
laid out this way — and it can be — the two ends of the 
paper should meet exactly. 



54 PATTERN MAKING. 



WORM WHEELS. 

THE WAY TO GET THE ANGLE OF TEETH, AND THE MAN- 
NER OF FASTENING THEM ON. 

A WORM-WHEEL pattern is not an easy thing to make 
by any means ; it is that kind of a job on which a good 
man is apt to go astray. 

Figs. 107 and 108 represent a wheel to be made; the 
worm is shown in gear, and as I have ah-eady referred to 
it, I will confine my remarks to the wheel pattern, except 
that reference will have to be made to the angle of 
thread of worm. 

The dimensions are the first thing to be determined. 
Let the wheel be 2\y^" diameter, lY^" pitch, 39 teeth, 
form of tooth, involute, laid out with the aid of Prof 
Willis' Odontograph. 

Pattern makers generally shape the thread of a worm 
pattern the same as the tooth of the gear in which it is 
to work ; but the sides of the thread should be straight, 
at an angle of 75 degrees with the axis of the worm. 
This is correct for an involute, because that is what a rack 
tooth would be, and the worm is similar to the rack in 
this case. A section of the wheel pattern is shown in 
Fig. 109 ; the rim is first built up and turned straight on 
the outside, the pattern being parted on line AB. 

A little thought will have to be exercised in building 
and turning the rim so as not to do any unnecessary 
chucking. In the first place, the face plate for turning it 



Fig. 105. 



Fig. 106. 




How to get the Lines for Thread of a Worm 




"'T'"' ' ' / Fig. 109. 



E 



illL 



WORM WHEEL PATTERN. 



Fig. lie. 



PATTERN MAKING. 55 

should be about the same diameter as the rim, so as to 
allow the ends of the teeth to be turned off. Lay each 
half up separately, with the parting joint of pattern against 
the face plate, rough off the outside and finish the inside 
of both halves, care being taken to turn the inside of both 
halves the same diameter, because of the chucking. 
This done, the rings are chucked by the inside, and, to 
do this, segments are nailed on the face plate. The out- 
side of the rim should now be finished to the size re- 
quired, and blocks for the teeth fitted on the periphery. 
These blocks should be fitted and glued on with the 
grain of the wood running at the same angle that the 
teeth are to be at the pitch line, the width of each block 
being the same as the pitch. The way to get the angle 
is shown in Fig. 110,7 representing the angle of tooth 
at the pitch line. These blocks are fastened on before 
taking the first half out of the lathe, and a groove turned 
on the joint for locating the halves concentric with one 
another. When the second half is chucked and turned 
and the blocks for teeth fixed on, as in the case of the 
first half, a projection is turned on the joint of it to fit 
the groove on the joint of the other. The two halves 
should now be put together, and the blocks for the teeth 
turned off on the ends, and finished, as seen in section 
Fig. 109. A good surface for marking out the teeth 
may be made by varnishing these blocks with yellow 
varnish. 

In Fig. 107, a part of the pattern is shown cut through 
line AB, Fig. 109; the other part, with the three teeth 
represents the outside and ends of the teeth. To be the- 
oretically correct the teeth should be thinner on the ends 



s^ 



PA TTERN MAKING. 



than on the parting line, AB, but in practice, this is not 
generally considered, because it would make it difficult 
to draw the pattern if made that way ; the teeth in cast 
gears are therefore made the same thickness on the line 
(7 as on the pitch line D in Fig. 107. 

The Odontograph for locating a center for marking out 
the teeth is shown at E ; the instrument is nothing more 
than an angle of 75° divided off in y^" spaces on one side 
for 4'^ in length, the y^" spaces being subdivided. Zero 
on the instrument is placed at a point on the pitch line, 
and the plain side is set to a radial line; the radius of 
the gear is then read off on the graduated side, which 
will locate a center from which to strike the tooth. In 
this case, the wheel being 2\y^" diameter, the radius is 
\oy^" ; read off 1 1, which is near enough for all practi- 
cal purposes. 

To lay out the teeth on the pattern at the proper 
angle, space off half the pitch from one of the joints of 
the blocks, on the pitch line each side of the wheel. If 
these pieces for the teeth have been made to the angle of 
y, Fig. 1 10, these points on each side will be the starting 
points for dividing the teeth, and will give the angle of 
tooth. 

II the toeth are marked out also on the joint of one- 
half of the pattern, and trimmed down to the line, it will 
be an additional guide to cut the teeth by. 

The fact of the arms of the pattern being in halves 
makes them thin, and therefore weak ; but if the joints 
in the center be tongued, and the hub on each side glued 
and screwed to the arms, it will strengthen them consid- 
erably. 




SWEEPING DRUMS. 



PA TTEhW ' . MA k'ING. 5 7 



SWEEPING STRAIGHT WINDING DRUMS. 

Fig. 1 1 1 shows one way of sweeping up hoisting 
drums. The usual way is to allow one or two fingers 
for sweeping the groove to travel the whole length of 
drum by means of a nut running on a long screw. It 
will be seen that the long screw is discarded and that 
the sweep is made the whole length that the drum is to 
be. This sweep is required to travel up and down only 
one thread, which will make a continuous thread, the 
same as if two fingers traveled the whole length by means 
of the screw. The set screws, E and F, are free from 
the spindle, so that the sweep may rise and fall as it is 
pulled around. It rises by means of a pinplate, B^ bolted 
to the bottom of the sweep, and which works in a spiral 
groove cut in the hub, A ; this groove must be cut the 
same pitch that the groove of drum is intended to be. 

Figs. 1 1 2 and 113 are other views of A and B. The 
spindle is kept from turning by the set screw, //, being 
set against it ; at the same time, the projection on the 
hub, A, fits into the slot G, in Fig. 1 12. 

After sweeping the grooved part of drum, the part C 
of the sweep may be taken off and a piece, like D, fas- 
tened to the upper cross-piece ; this is for striking the 
flange of drum and a step around the top for a guide 
by which to set the cope. While sweeping the groove 
the spindle remains stationary, but when sweeping this 



58 PATTERN MAKING. 

flange and step, it must revolve with the sweep ; to do 
this, the set screws, E and F, must be tightened, the pin- 
plate, B, taken off the sweep, and the set screw, //, loos- 
ened ; this will allow the spindle to revolve in its taper 
socket in the ordinary way. 

For drums over 6 ft. in diameter, it will be found 
necessary to support the top of the spindle with a tem- 
porary cross-beam, and also, to have a counterbalance 
weight to help the rising of the sweep as it is pulled 
around. 




i:"^ 



01^ I 



PA'J' TE RN MA KIA 'G. 5 9 



MAKING WINDING DRUMS FROM PATTERNS. 

METHOD OF CUTTING THE GROOVE. 

Fig. 1 14 shows a section of a Grooved Winding Drum 
about 3 ft. diameter, and Fig. 1 1 5 shows the way pat- 
tern may be constructed. 

Z> is a 4x4'' stick ; on it three discs, A, B, C, are 
fastened and screwed by brackets. Lagging to form the 
shell is screwed around these discs, while the spider in 
the end is loose and just laid on disc A, so that it can be 
lifted with the cope. C should be made about f smaller 
in diameter than A, to allow the core, shown in Fig. 
114, to be easily lifted; this \" taper on the drum will 
not be noticeable when cast, neither does it affect any- 
thing. 

Fig. 116 represents a piece of the lagging that is 
screwed on the discs, A, B, C. Fig. 117 is given to 
show how to get the proper angle of the groove; the 
distance, x, is the circumference, a the pitch, and y the 
angle that the grooves are to be cut. Fasten two pieces 
together in the form of a T square, like Fig. 1 1 8, for 
marking the lines on Fig. 1 16, and let the blade be cir- 
cular, to fit the face of the lagging. Also make a 
templet the same length and thickness of the drum, to 
mark off the grooves on the edge of lagging. 

As the outside is being rammed up, the screws that 
hold the lagging must be taken out, so as to allow A, B, 



5o PATTERN MAKING. 

Cy and D to be removed after the cope is lifted. Previ 
ous to ramming up the core, a flange, E, Fig. 114, i: 
placed in the bottom of the mould ; this flange is mad( 
in segments and is for bolting the brake wheel to th^ 
drum. After the inside is rammed up and lifted oul 
this flange, E, and the lagging are drawn in and th 
groove finished off and the skin dried. 

Some may say that a pattern such as I have describe* 
is very costly ; in reply I would say that it would sooi 
pay for itself by the difference in the cost of sweepinj 
and moulding, but drums of larger diameter should b 
swept up, as they generally are. 



PATTERN MAKING. 6 1 



MAKING SHEAVES FROM CORE-BOXES. 

I PROPOSE to give under this head some ideas for 
making sheaves of various kinds, and will first give the 
way for making large ones from core-boxes. 

The style of sheaves, shown with cast arms, is that 
which is used to transmit power on cable car roads. The 
groove is made to receive segments that are bolted on, 
and of which more will be said further on. The right 
hand side of Fig. 120 shows one arm and a portion of 
the rim ; as will be seen, this sheave is in halves, and 
arranged for bolting together ; joint E is to be finished 
so that stock for planing must be allowed at E. In Fig. 
1 2 1 two sections are shown ; that on the right is a sec- 
tional view of the mould through the arm-core, AB^ and 
that on the left through CD. These two sections repre- 
sent the mould closed, but in Fig. 1 20 I have shown the 
mould open, with the arms, F and G, set. The lower 
part of rim is made in green sand, a segment pattern 
being used to form it. This segment pattern is shown 
to the left in Fig. 1 20, H being a section of it. Two 
battens, a, b, are screwed on, which run to the center, 
the ends being cut to fit around the spindle. 

The lugs at the joint, for bolting the rim together, 
must be right and left hand on the segment pattern, 
using one when starting and the other when finishing. 
These lugs are screwed on temporarily. Care must be 



62 PATTERN MAKING. 

taken to divide the arms off accurately on a level bed. 
After marking the center line on the bed for each arm, 
move the segment around on the spindle and apply the 
center line of the core print for the arm core to the center 
lines on the bed, and, as lines on sand soon disappear, 
it will be well to drive a small stake on each side of the 
print for arm core, so that, when moving the segment to 
each division, the arm print can be set down between the 
stakes, and thus insure accuracy. It is particularly nec- 
essary to divide these arms off equally, so that the bolt- 
holes shall match those in the segments that ^o in the 
groove, for it is the intention that all the holes, both for 
bolting together the sheave and segments, shall be cast 
in, and to compensate for any difference that may occur, 
the holes are made a little long in the rim and lugs, as 
seen at^, Fig. 120. 

Fig. 122 is the arm core-box, and I will again remind 
the pattern maker that it should be made strong, or it 
will come apart, as I have often seen, and then there is 
trouble about the cores not coming together at the cen- 
ter as they should. 

Fig. 123 shows the way some pattern makers construct 
these large arm core-boxes ; the result is, they are 
rammed apart, as shown, and then the poor core maker is 
accused of using the core-box roughly. Just as in the 
case of arm box for fly-wheels, so this box should be 
made a little longer than is necessary for the present job, 
so that the end, K, can be 'moved out and the arm length- 
ened for a larger wheel whenever it may be needed. 
The interchangeable pieces, i, 2, 3, form the hub. 

Fig. 1 24 is the core-box from which the cope cores, Z, 



*^ £10' iS^ 



( Tio-^^^' 




JFig. 12 G. 




MAKING SHEAVES FROM CORE BOXES. 



PATTERN MAKING, 63 

in Fig. 121, are made. The same lugs, / that are used 
on the segment pattern, can be used in this box for two 
cores, using one right hand and one left hand. The box 
is shown arranged for the first core on the left. M is 
a loose piece half the width of the core print that receives 
the arm core. It will be seen that this box is made 
longer than the core is needed. This is to enable us to 
change ends with the loose piece, M, wiien making a 
core the opposite hand. The length of this box is from 
the center of the arm to the joint E, but the \" stock, 
which is allowed for planing the joint at E, makes the 
box \" longer than the eighth part of the half sheave, 
and therefore \" too long for the other cores, so that a 
\" piece must be put in the end of the box after making- 
two cores with the lug, /. 

Fig. 125 is the box for the groove cores. The section 
of this box shows it arranged for making the cores in 
two parts, to be pasted together at o 0, Fig. 121. The 
cope part of this core is a little different from the bottom 
part; a loose piece, g, in Fig. 125, is fitted in the bottom 
of the box, to be left in for the bottom part of core and 
taken out for the cope part. . The groove that this core 
is to form is turned on the two sides, but not in the bot- 
tom ; tool clearance should therefore be allowed on each 
side in the bottom to accommodate the turning. This 
is seen in the section at N. 

I have not shown any core-box for the slab core, /, as 
it is nothing but a plain core, and the box is smiple and 
needs no explanation as to making it. 

Fig. 1 26 is the core-box for the hub. It is made the 
depth of P, in Fig. 121. This view gives all the explan- 



64 PATTERN MAKIXG. 

ation that is necessary as to the way to make it. The 
faces, E, of the hub and lugs are covered with slab cores. 

Another type of sheaves is shown in Fig. 127. This 
style can be made considerably cheaper than those I 
have already described. Dispensing with the groove 
that receives the segments makes it very simple to 
mould, and also easier for turning the periphery of cast- 
ing. The plan for forming the arms and the hub is the 
same here as in Fig. 120. The segment pattern for 
making the green sand part of mould is seen in Fig. 128, 
of which Fig. 129 is an end view. The pieces that run 
to the center are not screwed on top of segment in the 
usual way, but on the step that is made in the segment 
at a, Fig. 129. By making it in this way, a large part 
of the rim can be made in green sand, as shown in Fig. 
130. 

The core-box for core A, is made in very much the 
same way as in Fig. 124. The segment that is bolted 
on the periphery of this sheave is moulded edgewise ; 
there are chipping strips on the inside at b, c, d, e, Fig. 
131 ; on the side,/, stock for planing is allowed, so that 
the segment may set straight against the flange of the 
wheel . 

I once had a little experience with some of these seg- 
ments. When the first lot of those in Fig. 131 were 
being fitted on the wheel, it was found they had straight- 
ened somewhat, just as represented by the dotted lines ; 
it was evident that these segments straightened in cool- 
ing, the two thin flanges, x x, cooling first and pulling the 
casting out of its true circle ; in the next, I took care to 
allow for this when making the pattern. 




Fig. 129 

MAKING SHEAVES FROM CORE BOXES. 



PATTERN MAKIXG, 65 

When there is a number of these sheaves to make, 
instead of closing the top with slab cores, as I have 
shown, it would pay to make a cast iron half ring wdth 
which to cover the top. This half ring should have a 
number of spikes on one side, and on it a thick coat of 
loam, struck off level, dried, and blacked. 



66 PATTERN MAKING, 



MAKING SHEAVES FROM PATTERNS. 

There is not much scheming required to make a pat- 
tern for a sheave, such as shown in Fig. 132, and yet, to 
show the way it should be made, may not be entirely 
out of place here, as I want to bring in a few points that 
have not hitherto been considered. 

I have said that into the groove of this style of sheave 
are bolted segments that take the cable. The advantage 
of this arrangement is evident, as it allows the segments 
to be renewed when worn out. I have shown in Fig. 
132 a part of the rim and a cross-section of the sheave; 
this shows the manner of bolting the segments to the 
sheave. The groove, into which the segments are bolted, 
is to be turned, but the groove of the segment is left 
rough. 

Chipping pieces are cast on each side of the segment, 
as seen at a, b, c, d, Fig. 133, because it is intended that 
the segment shall not bear in the bottom of the groove, 
but only on the chipping pieces by the sides, and at ^ ^ ; 
see cross-section. Fig. 132. 

Fig. 133 shows the pattern of the segment, and is 
made to be moulded on the edge, the groove being in 
the cope; it is desired to cast the bolt-holes, and care 
must be taken in spacing them off, because they are 
wanted to match those in the sheave, which are also cast 
in. I have marked the core prints for these holes ; the 
bottom print is made something like the cope print^ — 



mg. 132, 



% 



Fig. 13. 'J 




MAKING SHEAVES FROM PATTERNS. 



PATTERN MAKING. 67 

oblong — as shown at/; this is done in order that the 
core may stand in the mould more securely while tlie 
cope is being-^closed. If a round print were used just 
the size of holes, the cores would be top-heavy and diffi- 
cult to locate in the mould, hence the necessity of mak- 
ing the bottom print as shown. The core-box for this 
bolt-hole should be made as shown in Fig. 134. 

It is understood that these sheaves are bolted together 
in halves, so that in making a pattern, only one-half will 
be required. Proceed by building up and turning a 
whole ring, of which Fig. 135 shall be the section; A is 
the print for carrying the groove cores. After turning 
the ring, cut a stick the exact length of the inside diam- 
eter — this will be a gauge to see whether the ring has 
sprung after being cut in two, and, if it has, to bring it 
back to the gauge when fastening in the arms. After 
sawing the ring in two, glue and screw it together 
strongly, as seen in Fig. 1 36 ; but before doing so, it 
must be remembered, as before, that stock for planing 
must be allowed at the joints where the ring is bolted 
together, so that the pattern shall be \" over the half cir- 
cle. In order that this may be, the ring should not be 
cut exactly in halves, but \" one side of the center, mak- 
ing one part about \" short, not reckoning anything for 
saw cut — with saw cut would probably be \" short. 
Now, if after sawing the ring, two of the ends be brought 
together, it will only be necessary to build on one end of 
one of the sections. Having done this, the ring is ready 
to have the arms fitted in, which should be done by 
letting them in the rim, as represented by dotted lines at 
A B, Fig. 132. 



6^ PATTERN MARKING. 

Care must be taken not to fit the arms in so tightly as 
to spring the ring out of round ; this can be very easily 
done. After locating the arms, bore two I" holes from 
the outside of ring into each arm, and glue in hard wood 
dowel pins ; this will make a strong job. The small 
bosses, of which one is shown at C, Fig, 132, are turned 
and sawed out with a narrow band-saw to fit over the 
rim. This is done by inserting each boss in a block 
with a hole through it the size of the boss ; two views of 
this block are seen in Fig. 137. The boss is fixed in 
the hole D, and sawed to the shape of the inner part of 
rim. Of course, the block is fitted over the rim first, to 
act as a guide for sawing them out. 

The core-box for the groove need not be made with 
loose piece in the bottom, as in case of forming these 
sheaves with cores, because the cope closes down on top 
of print, and not on the dotted line, Fig. 136. 



liy. 13 S. \ ■ ■' 




Fig. 144. 







Fif/. 140 



I'iy. 143. 



SHEAVES WITH WROLXIHT IRUX ARMS. 



PATTERN MAKING, 69 



SHEAVES WITH WROUGHT IRON ARMS. 

AN ORIGINAL WAY OF MAKING THE HUB. 

The style of sheave shown in Fig. 138 is used exten- 
sively in mines for carrying rope; the arms, which 
spread on either side, act like stay-rods to the rim, 
making it very rigid sidewise, at the same time forming 
altogether, a light, but strong, sheave. 

To the left of Fig. 138 is shown a section of the rim 
with wrought iron arms cast into it ; to the right, a sec- 
tion of the cores which form the rim ; and at the center, a 
section of the cores forming the hub. 

The lower part of the mould is formed with green 
sand, the segment shown in Fig. 139 being swung 
around from the center, C. The cope is formed with 
cores made from box shown in Fig. 140. Fig. 141 is a 
cross-section of this box. 

While this is a good way to make sheaves of large 
diameters, for those under 8 ft. diameter a full ring 
is probably a better way, providing the ring can be 
stored so as to lie flat on its side, instead of standino- on 
its edge ; for, having no arms, a large ring standing edge- 
wise would soon become oval. 

The cores forming the groove are made in halves 
from the box, of which Figs. 142 and 143 are two views; 
these cores are pasted together at the joint. A, Fig. 138. 
Four round cores are made to form the hub ; these are 



70 PATl'ERX MAKING. 

set one on top of the other after making the lower part 
of the mound with the segment. The lower hub core, 
B, through which there is a hole, should be set over the 
pin from which the segment has been swung around. 
This will locate the hub concentric with the rim. Half 
of the arms should now be set in the mould, after w^hich, 
the two middle cores, C and D, are located. When C 
and D are being pasted together at the joint, E, care 
should be taken to get the holes that receive the arms 
exactly midway between those in the lower part. The 
center core, F, should now be set, then the balance of 
the arms and the top core, G. When pouring these 
sheaves, the rim is allowed to shrink all it will before 
pouring the hub, and in large ones, the hub is not 
poured until the following day. 

Figs. 144 and 145 are sections of the round core- 
boxes for the hub cores, CD and DG. Plenty of di'aught 
should be made on the inside of these two boxes ?X a a\ 
the half round prints for the arms are shown at b b. 

The small bosses shown in Figs. 146 and 147 are used 
in cope core-box. Fig. 140; the prints on these small 
arm bosses vary ; the cores which cover those arms run- 
ning upward from the hub, should have Fig. 146 in the 
box, and those which run downward, Fig. 147. The 
bosses on the segment are made similar. 



Fig. 148. 




SWEEPING CONICAL DRUMS. 



PATTERN MAKING. 



A MACHINE 

FOR 

SWEEPING CONICAL DRUMS. 

DESIGNED BY THE AUTHOR. 

It may not be understood by some why a winding 
drum is sometimes made conical instead of a straight 
cylindrical form, and it may not be entirely out of place 
here to explain the reason, for the benefit of such. 

Conical drums are used for winding heavy loads from 
deep mines. When the skip or load is at the bottom of 
the mine, ready to be hauled up, the winding on the 
drum begins at the small end, and, as the rope does not 
wind as fast on the small end as it does on the large end 
of the drum, it allows the slack rope in the shaft to be 
gradually taken up at the starting, and also prevents the 
load from starting too suddenly. The engines also gain 
a decided advantage when winding with conical drums, 
because, instead of the winding being started at full 
speed, it gradually increases, thus giving the engines a 
better chance to do their work. 

It is scarcely necessary to inform my readers that it 
requires a great deal more skill to build and properly 
secure a mould for a large conical drum than it does to 
mould a grate bar ; but there is a class that stands so 
high in the engineering profession, that to them all foun- 



72 PATTERX MAKIXG. 

dry work is just a little above unskilled labor — something 
requiring more brute force than an)1:hing else. Such 
ideas, though, do not prevail among our genuine and 
practical engineers ; they are only found among the cle\-- 
erly ignorant. 

All those v.ho have much to do with the machinery- 
business know what an amount of consultation and 
scheming is necessar\' before some jobs in a foundry' can 
be started, and then how it requires men of good sound 
judgment to execute the work. 

The building of a mould for a large conical drum is 
one of these jobs. The way of sweeping the groove, an 
arrangement for which I propose to describe, is only a 
small item of the work. 

In Fig. 148, A is the sweep that travels up and down 
the screw, B, as it is pulled around. The spindle, C, is 
secured to the cross, D, at the bottom ; the bevel gear is 
fast on the spindle, two set-screws in the hub holding it 
in place ; the bracket, E, is loose, and turns on the spin- 
dle ; it has a bearing at a, in which the pinion shaft runs ; 
the end of this shaft is carried by a tee piece that turns 
on the spindle. The pinion shaft and the screw are con- 
nected by a universal joint, while the screw is carried by 
two adjustable cun-ed pieces. F and G. Guide-rod, H, 
keeps the nut from turning on screw, B ; arm, /, fits over 
the bracket, E, and carries the curved piece, F] this arm 
is also adjustable. 

Now, it will be clearly seen that, if the arm, J, and the 
bracket, E, are pulled around, it will cause the pinion and 
the screw, B, to turn, thus making the sweep. A, to travel 
a certain distance ever\' time it goes around. The gears 



PATTERN MAKIXG. 73 

determine the pitch of the groove to be swept ; if the 
proportion of the gears are three to one, and the screw 
\" pitch, then the sweep will travel \\" at every turn, 
making a groove \\" pitch. When any other pitch is 
required, the gears must be changed for those of a differ- 
ent proportion, for instance, for a 2'' pitch drum the pro- 
portion of the gears would be 4 to i. Bracket, E, is 
made so as to permit the use of gears of different sizes. 

When a drum is wanted with a left-hand groove, the 
gear on the spindle is turned upside down, and located 
under the pinion instead of over it. The machine is also 
arranged so that a drum of any angle can be swept. 
This is done by loosening the bolt that holds part F in 
place, and by taking out those in the upper part, G, thus 
allowing the screw to be swung at any angle from the 
center of the universal joint. 

The reason for making the arm, /, separate from the 
bracket, E, is obvious ; it is to give a better chance for 
adjusting the lower part of the machine than the swing- 
ing of the screw gives. The pinion shaft runs in close 
to the upright spindle, so that when the set-screw in the 
pinion is loosened, the shaft can be pulled out to the 
required distance, and the set-screw in pinion be tight- 
ened again. Wlien this is done, it will be found necess- 
ary to bolt on the flanged sleeve, K, to the end of 
bracket, E, between the universal joint and the bearing, a. 
For building and sweeping up the mould roughly, the 
screw and pinion shaft can be disconnected entirely and 
a plain sweep made, bolting it to the upper and lower 
arms, y and /. 

The engraving only represents the model which I 



74 PATTERN MAKING. 

made of this machine ; the details of the machine proper 
will vary somewhat. For instance, where there are solid 
boxes on the bracket, E, for the spindle and pinion shaft, 
there should be caps, so as to make it easier to discon- 
nect the parts. The universal joint should also be made 
separate from the screw and pinion shaft; many other 
items would need changing when building a machine to 
do the work. 




IBBfBf 




ITEMS FOR PATTERN MAKERS. 



PATTERN MAKING. ^^ 



ITEMS FOR PATTERN MAKERS. 

It is surprising the amount of time and money which 
may be saved in the machine shop and foundry when 
attention is given in the pattern shop to what is some- 
times termed the smaller matter of the business. 
Usually the more important details do not wear us half 
as much as the ever-recurring little set-backs. For 
instance, how often it happens that the machinist has to 
chip away a cylinder head at A, like shown in Fig. 152, 
to prevent it from choking the port of the cylinder, when 
the pattern maker, might just as well have cut the clear- 
ance, on the head back far enough to clear the port yi" , 
and thus save the machinist's time. I do not think any 
M. E. w^ould be fine haired enough to object to the small 
amount of extra clearance space that this would give. 

Again, what unnecessary trouble might be saved some- 
times in chucking a casting in the lathe, if some lugs or 
other projections, that could easily be broken off the 
casting, had been put on the pattern to facilitate the 
holding of it. I have often seen a machinist with a 
casting on the planer or lathe puzzled how to hold 
the " blamed thing," as he would name it, from jumping 
out of the machine, when perhaps a little foresight in the 
pattern shop would have made matters easy. A good 
pattern maker will consider these things and look ahead, 
following his job in imagination through the foundry and 
into tlie machine shop. 



76 



PATTERN MAKING. 



Another thing along the Hne of items, and which is 
generally overlooked : when a cylinder casting has to be 
lagged with black walnut, the pattern maker should make 
provision on the backs of the flanges for surporting the 
lagging, similiar to that shown in Fig. 150, This is a 
much better method than blocking the lagging off from 
the body of cylinder with blocks fastened on back of 
lagging. 

The edges of the flanges at x, Fig. 151, should not be 
rounded off, as is often done. When flanges are extra 
wide, they might be cored out by setting a ring core on 
the backs of flanges, similar to that shown in Fig. 151. 

By providing for the cylinder lagging this way, a 
better and cheaper job can be done than otherwise, when 
no provision is made. 

Stamping or marking with black varnish the diameter 
and length of all core prints, on every pattern is very 
simple, and apparently unimportant, and yet if this prac- 
tice were general, I fancy the moulders would pronounce 
an everlasting benediction on the pattern makers, espe- 
cially the moulders who never have any calipers or rule — 
in fact, it would be an all-around convenience and a 
preventive of mistakes. 

Many circular pieces of work in the foundry are 
covered with slab cores to save ramming up a cope, and 
a core-box for these is usually a very simple piece of 
work, and yet nine times out of every ten the cores 
when made and located do not fit on the ends, but will 
remain open, either on the inside or outside in the 
manner shown in Fig. 149. If the moulder should butt 
the ends closely together, the cores would not cover the 



PATTER AT MAKING. 



77 



mould, but would run off somewhere on the outside or 
inside, as the case may be. Now, I do not mean to say 
a pattern maker cannot make a core-box of this kind, 
and not make the ends radial, so that the cores shall fit 
closely together when laid down, but there is a very 
simple way by which the ends of these slab cores can be 
made to fit without any trouble to the moulder, and that 
is, by making one end round and the other hollow, as 
shown by dotted lines in Fig. 149. By this method the 
ends can be kept close together, and the cores located in 
their proper place when covering the moulds. 

The amount of stock that should be allowed on a 
a pattern for finishing in the machine shop is a source of 
trouble to some pattern makers. Among the first ques- 
tions that many will ask their foreman when given a new 
job, are, "How much stock shall I allow for boring?" 
"How much for planing?" and so on. It is almost 
impossible to establish any rule that shall be uniform as 
to the amount of extra stock that should be allowed — for 
while yi" is not enough for some jobs, for others it may 
be too much. Circumstances and a workman's good 
judgment can alone determine the proper quantity to 
allow. 

A dry sand casting will not shrink or strain as much 
as a green sand one, and in large work the shrinkage is 
uncertain, so that before a pattern maker can intelligently 
allow the desired amount for finishing, he should know 
the conditions under which the casting is to be made, 
and it will help him in his conclusions to get acquainted 
with the style or manner in which the moulders are 
accuf*:omed to ^'lrn out work, for in some foundries the 



-3 PATTERN MAKIXG. 

moulders will put on all the stock necessary for finish, 
and a great deal more, without the pattern maker 
allowing any. 

It makes all the difference in the cost of a piece of 
large machine work, which has to be turned or planed to 
correct measurement, whether the machinist has to take 
three or four roughing cuts or just one; whether he has 
to take off an inch and a half, where a quarter of an inch 
w^ould have answered. Then, again, the pattern maker 
must not be too "skinny" about allowing stock, or he w-ill 
give the machinist more trouble than by allowing too 
much — of the two evils, too much to take off a casting 
is rather to be desired than not enough. Insufficient 
stock on a complicated casting will make a machinist 
bless the pattern maker in a manner not too compli- 
mentary. 

One-quarter of an inch ( i^-inch in the diameter) ought 
to be enough for boring out say a 20'' x 48'' cylinder, but 
if the same amount only was allowed on a \o" yi J2" 
cylinder, the bore in all probability would not clean out 
to proper size; y^" or ^'' would not be too much on 
such a large cylinder. 

On some castings the stock allowed on the cope side 
should be more than on the drag side ; for instance, a 
large crank disc, a Corliss cylinder and many other jobs. 



^,OOS>' Jtitlff 




Fig. 153, 




Fig. 156. 



PATTERN MAKING, yg 



BUILDING UP SPUR GEAR PINIONS. 

If spur gear pinion patterns, with about y" face and 
upwards, were built up hollow, with a cover on the cope 
side, which could be removed as shown in Figs. 153 and 
154, the moulder would be more likely to get a casting 
like the pattern. 

By leaving the cope side of the pattern open this way, 
it allows the moulder to rap all arouud on the inside of 
the pattern, which is a much better way of loosening 
the pattern than driving a spike in on the top, and ham- 
mering the spike sidewise, until the mould is enough 
countersunk to produce a bevel pinion instead of a spur 
pinion. 

Building the pattern this way not only helps the 
moulder, but also makes it convenient for fastening the 
teeth on with screws from the inside, using a short 
screw-driver to do so. 

For drawing the pattern, an iron plate with a tapped 
hole should be inserted on the outside, in the end that is 
moulded down, and a hole bored through the bottom — in 
this way the draw plate will not be so liable to be pulled 
out as if put on the inside. 

The ring forming the shrouding over the teeth should 
be cut into segments in the manner shown in Fig. 155 — 
in this manner the shrouding can be drawn in, thus doing 
away with the parting in the bottom of mould, which 
would have to be made if the ring were whole. The 
shrouding need only be carried to the pitch line of teeth.. 



3o PATTERN MAKING. 



FOUNDRY CORE-BOXES. 

Pattern makers are not supposed to make a core-box 
for every round core that may be required, except 
in cases of special sizes, or when chambered holes are 
called for. Foundries usually carry a stock of what are 
known as round cores of ordinary sizes, though it would 
be a libel on most foundries to call them round or say 
they are ordinary sizes. 

I suppose the reason why foundry stock-cores have 
such a bad reputation is because there are so many cores 
constantly being made from one box, and the " artist in 
cores " becomes so attached to his " standard core-boxes " 
as to be unable or unwilling to discern when they are 
unfit for further service — no matter what condition the 
box be in, it will always stand to make a few more cores. 

This is why castings come into the machine shop 
with a 2^' round hole (or rather what is supposed to be 
such), measuring all the way from 2" to 2^^'' — all 
depends what part it is measured. 

A core-box that might do better service than the 
ordinary one is shown in Fig. 156. It can be made of 
iron or brass, according to size required. It will be seen 
that it represents a box \2" long, spaced off in inches, 
a cut being made at each division with a hack saw, 
enabling the core maker to cut the core, while green, to 
the ^-equired length, by drawing a thin trowel or an old 



PATTERN MAKING. 8 1 

hack saw through one of the cuts. For an inch on one 
end it is spaced off in eighths — this gives the core maker 
an opportunity to practice " fine measuring " when 
cutting the core, but these eighths may be dispensed 
with, according to taste. 

For large sizes the box should be made longer — how 
much longer depends upon the class of foundry work 
done. I am of opinion that if some enterprising firm 
were to make a line of half round iron core-boxes, 
something after the style shown in Fig. 156, and get 
them up light, they would find a ready sale for them in 
foundries all over the countiy ; it would be meeting " a 
loner-felt want." 



82 rATTERN MAKIN 



MAKING AMMONIA PUMP CYLINDERS. 

There are few firms manufacturing ice making and 
refrigerating machinery, which have not had some trouble 
at some time with their pump cyhnders and other details, 
which have to withstand a high pressure. 

When a casting is being tested, the leak, if an}% 
appears in some corner of the casting, such as at the 
back of a flange where it joins the body — this is tlie 
most probable place for the defect to show itself, owing 
to the counter-shrinkage that takes place just at that 
point. A large fillet in the corner will sometimes help 
to prevent defects, but it is not always sufficient, espe- 
cially where large flanges are cast on the body of a 
cylinder. 

Pump cylinders for ice machines usually have large 
flanges, and to prevent the iron from drawing away in 
the corner at the backs of these flanges is one of the 
problems that the moulder has to solve. 

I was in a foundry not long ago, where they resorted 
to what I consider a good way to prevent the iron from 
being too open in the corners, as, indeed, all castings are, 
wherever there is a point at which counter-shrinkage 
takes place. It was done by placing chills in the corner, 
at the back of the flange, the chills being rammed up 
with the pattern. This, of course, chilled the iron in the 
corner, making it closer grained than it otherwise would 
be, and it had the desired effect of producing good cast- 
ings, that would stand the test without leaking. 



PLUG VALVKS. 




Anurican MachinUt 



PA TTERX MAKING. 



83 



PLUG VALVES. 

There have been so many improvements made in valves 
in recent years, that the ordinary plug valve is becoming 
almost a thing of the past. One of the reasons why 
many engineers have discarded the old forms is the liabil- 
ity of the plug or tumbler to fasten itself so tightly in the 
shell as to make it hard to turn. The cause for this 
" sticking fast," as it is generally termed, is not always 
the one so' often given, viz., corrosion, but is rather the 
unequal expansion of the plug and shell, sometimes due 
to the bad proportioning of nietal in the two parts, and 
by making the shell of cast iron and the plug of journal 
metal. The making of these two parts from different 
metals may prevent corrosion, but it rather increases the 
tendency to unequal expansion. 

I^iS- 157 is a section of a form of plug valve known 
in England as the " Etchell Tap," and is used mostly as 
a blow-off valve. The advantage claimed for this design 
over the old style is that it will not stick fast in its seat. 
The plug being inverted, a better distribution of metal is 
obtained, permitting the steam or hot water to circulate 
all around the inner parts of the valve, distributing the 
heat, by which means unequal expansion is obviated to 
a very large extent. 

It is not intended under the above heading to discuss 
the merits of valves, so much as to show the manner of 



g.. PATTERN MAKING. 

constructing the patterns and core-boxes ; yet these few 
general remarks will not be out of place. 

The pattern for the body of the valve is parted through 
the same plane as that of the section. Fig. 158 repre- 
sents half of the pattern of the shell or body without the 
bonnet and stuffing-box. The ball part of this shell, and 
the two core-prints, are turned between its two centres 
A B, while the inlet piece is turned separately and 
fastened to the ball part, the latter being cut off flat to 
dotted lines for that purpose. 

For large valves it is advisable to build up this pattern 
hollow, of segments, instead of making it solid, as shown, 
because a large solid block will shrink and crack, in 
which case it generally becomes necessary to plane off 
the joint of the pattern, to make the halves fit closely to- 
gether again, as they should. 

By referring to the section in Fig. 157, it will be seen 
that two core-boxes are needed for the shell, one for 
coring the space inside the conical part, and the other for 
the outside. Let these two spaces be disignated C and 
D. The core-box for the space D is shown in Fig. 159, 
and as two half cores made from this box would not 
match each other if pasted together, the box is arranged 
so that the cone E can be taken out and located at F, by 
which means half cores can be made that will match 
each other when put together ; a b is ?i core-print let in 
flush with E — before rolling the core over on a plate, the 
cone E is drawn out and the space filled with green sand. 

Fig. 160 is a core-box for the space Cm Fig. 157, and 
is pasted in the main core D dX a b when dry. The 
view to the left represents the side \iew of this bo?c. 



PA TTERN MAKING. 



85 



Fig. 161 is a pattern of the tumbler, or valve, as seen 
in the section in Fig. 157. This pattern is intended to 
be moulded on end with square part G down. The core, 
which is shown by dotted lines, is carried by the two 
core-prints marked c d. Notice that these two prints, of 
which /is an end view, are carried nearly to the end of 
the pattern. This, of course, is necessary for the sake of 
moulding, and for dropping in the core ; but provision is 
made in the box at x x, Fig. 162, by which this part of 
the print is filled in by the core, so that the moulder is 
saved the trouble of building over the core. 

It is unnecessary to show here the way of making the 
patterns for the stuffing-box and gland seen in Fig. 157, 
as they are so easily made that it would be uninteresting^ 
to ordinary pattern makers. 



35 PATIERX MAKING, 



GOVERNOR VALVES. 

The two sections in Figs. 163 and 164 represent a 
valve that is not only used on governors, but is very often 
used in water tanks to regulate the supply of water, a 
hollow ball that floats being attached to the valve lever 
in the usual way. 

In Fig. 163 the rotating valve a is shown in place with 
the two passages almost wide open, but in Fig. 164, 
which is a section of Fig. 163, through A B, the valve 
is removed, and is represented in Fig. 165. 

There are ways of making the pattern and core-boxes 
for this style of valve other than are given here, but the 
method represented by the illustrations has been chosen 
because it is the way the writer would adopt. 

Fig. 166 is the pattern which is parted on line CD, 
or, in other words, the joint of the pattern is the same 
as the outline of the section. Fig. 163. There is nothing 
to prevent the pattern from being parted on line A B, 
that is as Fig. 1 64 shows, but this would necessitate set- 
ting the cores in the mould in not quite so good a way 
as they can be, by parting the pattern on C D, and 
moulding it as represented in Fig. 166. Not much 01 
this pattern can be turned in the lathe, but the flanges, 
prints, and a small part of the inlet and outlet, therefore 
the part which surrounds the valve chamber, will have 
to be worked off by hand. 



Fig- 1G3 




PATTERN MAiaArc. g^ 

The flanges arc inserted in a groove in the same 
manner as shown in the article on plug valves. 

Figs. 167 and 168 are two views of the core-box for 
valve chamber c and outlet b in Figs. 163 and 164, while 
Figs. 169 and 170 are two views of the box for the inlet 
d, and the space e outside the valve chamber. 

The core-box for ^ <: is shown parted in Fig. 168 on 
line E F, Fig. 167 being a view of the joint on the face ; 
f g are core-prints for the ports. Cores from this box 
need not be made in halves and pasted together in the 
ordinary way, as they can be made whole and dried 
easily otherwise. 

The box in Figs. 169 and 170 is not so plain as the 
one just mentioned, though it is by no means a difficult 
box to make. By examining the two views of this box, 
it will be found that it is made in four parts — Jl, i, j\ k ; 
if the bottom be counted it will make five. Fig. 1 70 is 
a section of Fig. 169 on Hne G H — the joint hne x in Fig. 
170, shows the two pieces j and k parted and dow^eled 
together; h fits over the ends of 7 k, while the circular 
part i is made loose from h. This core also can be made 
whole, pasting being dispensed with. 

When ramming up this core, the top side of the box 
will be Fig. 169; after it is rammed up, party is taken 
off and a plate laid on top of the core, and the remain- 
ing parts of the box with the core are turned over on 
this plate. The bottom is then taken away, i drawn up, 
and // drawn aw-ay sidewise. Nothing now remains but 
to take off k, when the core will be left standing on the 
plate, on wdiich it can be dried. 

In Fig. 171, the tw^o cores made from these two 



gg PATTERN MAKING. 

boxes are shown connected, the two prints y"^ having 
formed a seat in b r for d e \.o rest in. In Fig. 167 the 
prints are carried flush with the top of the box, but the 
ports are only wanted the length indicated, by arrow 
points. This is to alUow core d e X.oh^ set into the core 
/; <f, after which small pieces of cores are nailed or pasted 
into the upper parts of the slots which have not been 
filled by d e. 

The dotted lines in Fig. 163 represent the bonnet x in 
Fig. 164, but as this with the other details, are plain and 
simple patterns to make, it will be out of place to fill 
valuable space with a description how to make them. 



t'tg. 172, 




DOUBLE-BEAT VALVES. 



PATTERN MAKING. 89 



DOUBLE-BEAT VALVES. 

The object of double-beat valves is to obtain a greater 
passage for the steam or water than can be had with 
single-beat valves of the same diameter and lift. They 
are sometimes called " Cornish " double-beat valves ; this 
may be due to the fact that they are used in all large 
pumping engines made in the county of Cornwall, Eng- 
land. 

There are many types of these valves, some being de- 
signed for pumps, and others for engines. One that is 
suitable for pumps is shown in Fig. 172, while Figs. 173 
and 174 are two views of one suited for engines. The 
pump valve has gun metal seats inserted 2X a a and b b, 
but in Cornwall the " Bal Cap'ns " (mine managers) favor 
tin seats. 

The valve and cage in Fig. 173 are usually made en- 
tirely of gun metal. Fig. 174 is a half section and a 
half plan of Fig. 173, and it is proposed to make these 
two patterns as shown in Figs. 175 and 176. Some ex- 
ceptions may be taken to this way of making them, pref- 
erence being given to solid patterns, with core-boxes for 
coring out the inside. This latter method would cer- 
tainly give much stronger patterns, but by constructing 
them as shown, the amount of work in the foundry would 
be considerably reduced by not having any cores to make 
or set, except those for lightening the upper part of the 



90 



PATTERN MAKING. 



valve cai^e at c c. However, should the pattern appear 
not strong enough for constant use (though it probably 
would be under ordinary circumstances), a metal pattern 
might be made from the wooden one, double shrinkage 
and finish being allowed on the original. 

By referring to Fig. 175 it will be seen that the pat- 
tern for the valve cage is parted dX d d for the conveni- 
ence of moulding, it being intended to mould it in a 
three-part flask, allowing one part of the pattern to be 
drawn in an opposite direction to the other, as indicated 
by arrows. The seats should be cast down, to insure 
perfect surfaces. The four side pieces which divide the 
four openings should be mortised firmly into the upper 
ring, and two dowel pins glued and driven down through 
into each, as represented by dotted lines. The lower 
ends of these four side pieces are not secured to the 
lower part, but doweled together for parting. 

It will be well to give the upper ring plenty of draught 
on the inside and outside, for, as it has to be turned and 
bored, it will not effect anything by so doing ; also give 
the four side pieces plenty of taper — it will make a 
wonderful difference in the moulding. 

Figs. 177 and 178 are two views of the core-box for 
coring out the upper ring, and the print to receive the 
segmental cores from this box is shown at ff. These 
cores will have to be secured in place by nails. In Fig. 
174 it will be seen that there are small bridges at g g, 
which are formed in the core-box, print // being a con-' 
tinuous ring. In Fig. 175 A represents one section of 
the mould ; at present it is the top, but it will become 
the bottom, as the mould must be " rolled over " — as the 



Fig. 173 




American Machinist 



PATTERN MAKING. e) 1 

moulders say — in order to cast the faces of seats down. 
After lifting off A, that part of the pattern having the 
rin^'- and four side pieces attached is drawn out, and the 
cores set in the part of mould just lifted. It is optional 
on the part of the moulder whether he puts on top A 
again before rolling over the mould, or rolls it without 
doing so ; it is probably safer to put A on again, as it 
will support the centre while turning over. When this 
is done, section B of the mould is lifted off, and the re- 
maining part of the pattern is drawn off. 

The pattern for the valve (Fig. 176) is also made to 
leave its own core, like the cage, and is built up with 
segments ; it is parted at e, one part being turned to fit 
into the other. The upper arms are made fast, but the 
lower ones should not be fastened in ; the reason for this 
will appear later on. This valve pattern is parted at e for 
the same reason as the cage pattern in Fig. 175 is parted 
at d d, that is, for convenience of moulding, but the pro- 
cess of drawing these parts of the pattern differs from 
that in Fig. 175. The upper and lower part of the valve 
cage were drawn in opposite directions, as was explained, 
but the upper and lower part for the valve will be drawn 
in the same direction. 

The valve is moulded and cast in the same position as 
shown in Fig. 176. After the cope is taken off, as rep- 
resented, the pattern, as far as the joint c, can be drawn 
out, after which the cheek E may be lifted, allowing the 
lower part of the pattern to be drawn also, and leaving 
the loose arms behind. Before these arms can be taken 
out, the cheek E and cope must be put back in place, 
and the whole mould, with the bottom E, rolled over. 



92 



PATTERN MAKING. 



Then F is taken off in order to draw out the arms ; the 
joint of i^runs along line k to /. 

These two patterns being completed, let us start in on 
the pump valve in Fig. 192, which is shown opened, the 
passage of the water being indicated by arrows. 

Figs. 179 and 180 are two views of the pattern, for 
the stationery part C, and Figs. 181 and 182 for the 
valve D, which lifts up and down on the seats a a and 
b b in Fig. 172. 

Fig. 179, like Fig 175, is cast the opposite way to that 
shown ; this is done in order to get the valve-seats free 
from dirt. The ring M\?, loose, but iVis fastened to the 
four wings. The centre guide P is also made loose, so 
that it can come away with the drag section of the 
mould. Fig. 179 represents this section of the mould 
taken away, but P is left behind for the sake of expla- 
nation. The four wings and the part N of the pattern 
are now ready to be drawn out of the sand, and this 
being done, the round end core that cores out the centre 
guide R, Fig. 172, should be set and tied down in the 
drag or lower section of the mould, and as there is no 
other place for the vent to be taken off, it will have to 
come off through the bottom, the bolt hole being drilled. 

The reason for setting this core now is to save lifting 
off the middle after it has been rolled over onto the drag 
with the cope, for it is clear that if thie round end core 
was not set before the middle was set onto the drag, that 
the core could not then be located. 

The reader must now imagine the whole mould to be 
turned over in the position in which it will be cast, and 
with the cope taken off; he will then see that it is only 



PATTERN MAKING. g^ 

required to draw the loose ring M out, and close the 
cope to complete the mould. 

As to the valve D, a glance at the two views of the 
pattern in Figs. i8i and 182 will show that there is 
much less work about this pattern and the moulding than 
the one just described. Like the other style valve, it is 
cast in the same position as shown in Fig. 181, and the 
pattern is made in two parts, coming apart at ^ z. The 
four arms seen in Fig. 182 are half-checked together at 
the centre, and four corner pieces glued in, to form the 
hub. These arms are let into the ring at i" j, 5 s, Fig. 
182. The projection on the inside, seen in Fig. 181 at 
r r, is made so that when the casting is bored out at that 
place there will be a clearance for the wings in much the 
same way as in the counterbore of a cylinder where the 
piston runs over. 

There are six ribs on the outside, which are numbered 
in Fig. 182. They are intended to prevent the valve 
from springing. The moulding of this pattern is similar 
to that in Fig. 176. 

In many cases the best way to explain how a pattern 
should be made is to describe the manner of parting the 
mould. This is the plan that the writer has partly pur- 
sued in this article, the purpose being to make it clearer 
as to the way of constructing the patterns than other- 
wise could be done, though to very many readers a 
glance at the illustrations will be all that is needed in 
order to understand the way in which the patterns are 
made. 



Q4 PATTERN MAKLWG. 



SCREW PROPELLERS. 

Imagine a cylinder similar to that in Fig. 183, whose 
diameter is A ; the curved line from a\.Qbon the periphery 
represents the thread of a screw which goes exactly once 
around this cylinder, starting at a and ending at b ; the 
distance from <^ to ^ is the pitch. Now if a right angle 
triangle be constructed, whose base equals the circum- 
ference of the above cylinder and the height equal to the 
pitch, the hypothenuse of the triangle will represent the 
thread from <^ to ^ unwound; that is to say, if a piece of 
paper is cut the same shape as the triangle and wrapped 
around the cylinder, the a c would develop the thread on 
its surface. To continue the thread, space off the pitch 
as many times as may be needed from a, and draw lines 
parallel to a c, as shown by dotted line B ; then d will 
meet a when wound around the cylinder, thus making a 
continuous thread. 

Tliis simple method is the one used for marking the 
thread on the pattern for a worm pinion, and which som.e 
pattern makers regard as a very profound bit of wisdom 
that should not be allowed to become too common by 
" telling." 

The line of the thread on the drawing, as shown in 
Fig. 183, is of no value for a working drawing; but 
the manner of developing this curve is given for the 
benefit of the beginner. It will be readily understood 



PATTERN- MAKING, g,;- 

without explanation, by referring to the cross lines which 
are numbered. 

If a three or four-blade propeller is wanted, a pattern 
for one blade is all that is generally needed, in which 
case the moulder rams up one blade at a time, moving 
around the pattern on a spindle. 

I have seen whole patterns made for three or four- 
blade propellers, five and six feet in diameter, which saves 
much time in moulding, but unless the pattern is to be 
used often, which is not generally the case, it seems to 
be more oconomical to make but one blade, especially 
where pattern storage is limited. This, however, is en- 
tirely a matter that circumstance alone can decide, and 
be that as it may, the same principles here given for 
building one blade will also apply to a pattern w^th three 
or four blades. ^ 

The style of blade chosen to illustrate the manner of 
building the pattern is that which is used on tugboats 
and river steamers. 

Fig. 184 is a plan of the blade, and Fig. 185 the end 
view. Being a true pitch it is an easy matter to get the 
angle at which to build the blade. First draw^//, which 
shall be the center line of the hub lengthwise ; c, in the 
triangle already referred to, is the angle that the blade 
must be on the end. Let this angle, tlieref(M-e, be made 
at c (Fig. 185) by drawing the dotted line g g across ff; 
then the point x, where these two lines intersect, is the 
center of the blade, as represented hy Ji h in Fig. 184, 
and through which the face must pass. 

Having located the center lines kh,ff^nd the angle 
e, proceed to lay out the hub, the outline and longitu- 



96 



PATTERN iMAKING. 



dinal section of the blade. The section shows the actual 
thickness through the center of the blade lengthwise, 
while the outline is not the actual but a projected one. 
The section across the end of the blade ii (Fig. 184) is 
seen at //(Fig. 185). To get the cross-section of the 
blade at the hub the angle must first be made. This is 
done by drawing lines from k k (Fig. 184) until they cut 
the same upper and lower lines as gg does. Then k k 
in Fig. 185 will be the angle and section of the blade at 
the hub ; k k, falling as it does on the round surface 
of the hub, will not appear straight, as shown, but it is 
drawn so in order to simplify the drawing, and as it 
is intended for a pattern maker's zuorking drawing it \\\\\ 
answer. The cross-section tsX. 1 1 and in in is omitted 
from both views to prevent a confusion of lines. 

We now have all the lines that are needed to get the 
stuff out for the pattern. Care must be taken to get 
each course of parallel thickness, for if they are not, the 
building up will give trouble and cause the pitch to be 
wrong. A glance at the face of the blade in Fig. 185 
shows Ave are dependent on the joints as a guide for 
shaping the face. For the sake of explanation, the stuff 
is cut as close to the line on the back of the blade as 
it is to the face line, but I would advise that for cutting 
off there be more stock allowed on the back than is rep- 
resented in the drawing. 

Figs. 186, 187, 188 show the shape of the first three 
courses, i, 2, 3. The width of each end appears in Fig. 
185, and the width ^\. k k is obtained by striking a radius 
on each course equal to r in Fig. 1 84, and then trans- 
ferring the different widths as seen at the section k k in 
Fig. 185, adding some for fillet. 



Screif Proin'lh't's 
Fig. 189 




Guide avd Support for end of Blade 
ivhile building 



PATTERN MAKING. g>j 

In getting out the courses the grain of the wood 
should run as shown in the direction of arrow in Fig. 
187; this will make the cutting and shaping of blade 
much easier than if the stuff were sawed out with the 
grain running straight. 

A wood pin should be turned the same diameter as 
the spindle, on which the blade will be moved around 
(say 2]/%"), and a hole being bored through the hub part 
of each course to fit the pin, they are slipped over the 
pin, thus keeping all the courses concentric. 

Though each course may be of even thickness, and 
the correct bevel laid out on the end of each piece, there 
is danger in the building up of the courses of their lean- 
ing over too much. To prevent this it is a good plan to 
get out an angle piece, as seen in Fig. 1 89, which is simi- 
lar to that used when sweeping a propeller. This being 
cut to the same angle as the triangle in Fig. 183, and 
made to fit the same circle as the diameter of propeller, 
it is used as a guide and support for building up the 
blade. Each course for a short distance in from the end, 
is beveled off so as to rest on the incline of this angle 
piece, care being taken not to destroy the upper radial 
edge in doing so. 

While this pattern is shown built face down, with the 
ends of each course resting on the angle piece, it may be 
built face up, and by some the latter method is preferred, 
because it is claimed that the pattern maker can better 
see to keep the face edges right when they are on the 
upper side, than on the lower ; but this is only a matter 
of choice. 



98 PATTERN MAKING, 



GEAR TEETH. 

In the following pages there are a number of teeth 
laid out, full size, from one inch pitch to three inch, ad- 
vancing by quarter-inches. 

There are fourteen separate teeth in each pitch, suit- 
able for gears having from fourteen to eight hundred 
teeth ; they have been laid out from Prof Robinson's 
Templet Odontograph and are interchangeable. The 
clearance allowed between the teeth is ^^ of the pitch, or 
in other words, the space is f^V ^^id the thickness of tooth 
tVo of the pitch ; the height of the tooth is f of the pitch, 
and the distance from pitch line to top foV o^ the pitch. 
These are the proportions generally used, but the thick- 
ness of a tooth may be changed, giving more or less 
clearance between the teeth of a gear, as circumstance 
may require. 

It would be impossible in a book of this kind to give 
the profiles of gear teeth which would serve all cases, so 
that I have confined myself to the system that is gener- 
ally adopted, and known as the Interchangeable System, 
that is, all spur gears of the same pitch made under this 
system will run together. For special gearing and bevel 
gears other settings are preferred; those which I have 
taken are on each tooth, the setting for the flank being- 
marked on the inside of pitch line and that for the face 
on the outside. 



PATTERN MAKING. qq 

The numbers show how many different size wheels 
can be made with same size tooth ; for instance — 42 to 47 
means that the same shape tooth will answer for gears 
which are to have from 42 to 47 teeth. 

A templet can be made from the profile of any of the 
teeth drawn, and fastened on a rod and used in the same 
manner as the Odontograph itself in Fig. 96 ; or, if pre- 
ferred, the thickness of a tooth at the top, pitch line, and 
bottom, may be taken and transferred on a piece of sheet 
zinc, and the curves struck by the aid of the Odonto- 
graph and settings given, without the usual working lines 
for locating the instrument. This latter way may obviate 
any discrepancy in the engraved teeth. 

At the end of the book will be found a plate in which 
some of the teeth are shown in gear, together with the 
way they should be made. 



100 PATTERN MAKING. 



MAKING WHEELS IN HALVES. 

A VERY common practice in making large wheels is 
to cast them in halves by setting a cast-iron plate, or a 
core in the mould, cutting the hub entirely through and 
the rim partially, leaving sufficient metal on the outside 
to form a bearing surface after it is broken and bolted 
together. 

This method of putting together large wheels of any 
kind cannot be considered first-class, and while it may 
be good enough for some wheels, for others it is not. 
A better way is to allow stock on one side of the centre 
line of each half of the wheel to permit of planing the 
joint ; that is, to make the wheel larger in diameter one 
way than the other, or the joint may be planed without 
allowing any stock for so doing, in which case plates to 
go between the joint are planed to a thickness corre- 
sponding to the amount taken off both halves, and 
doweled on the surface of joint, but this does not give 
such a satisfactory job as making the two parts of the 
wheels a little over the centre line, as already stated. 

Gear wheels which are to be in halves should never, 
in my opinion, be bolted together with a break joint, 
though this is often done, and, in making this statement, 
I am probably running against many who think 
otherwise. 

It may be argued that to make a wheel in halves with 
a break joint is a much quicker way, and, therefore, costs 



ind Cetitiy Line 




Fig. 193 




PATTERN MAKING. lOi 

less than with a planed joint. It is a much quicker 
method, but whether it costs less in the end is a 
question, for sometimes a break joint in a wheel, and 
especially a gear wheel, gives considerable trouble after 
it has been running for a short time. The grain of the 
iron in large wheels is not usually very close, but is 
what foundrymen call " open,' and the coarse particles 
of iron in breaking are torn asunder in a way that it is 
almost impossible to bolt the joint together twice alike, 
or to have a solid bearing, because the particles do not 
fit perfectly into the small recesses from which they 
have been torn; the result is that the joint chafes and 
becomes loose after working awhile, and when tightened 
up will make the wheel run out sidewise. 

To make a gear wheel in halves with a segment pat- 
tern, as represented in Fig, 190, with stock on the joint 
for planing, requires care and skill on the part of the 
moulder; with a gear moulding machine, the machine 
does the spacing, but in this case the moulder and pattern 
maker are partners, and are together responsible for the 
correct spacing of the teeth, and with care a gear can be 
made with a segment pattern that for a cast gear will be 
practically correct. 

The pattern of the segment is built up in six courses, 
and in doing so every other course is cut in two. The 
usual way that pattern makers have in building up a 
large segment pattern of this kind, is to glue all the seg- 
ments together, with the grain of the wood running one 
^^ ay ; the result is that after a time the pattern springs 
out from the original circle it was v/orked to. A pattern 
maker would not think of building up a whole circle this 



I02 PATTERN MAKING. 

way, neither should he a segment pattern that has to be 
kept to a certain arc Hke a gear segment. The thing to 
do after cutting every other course in two pieces, is to 
turn the two parts " end for end," as they say in the 
shop ; this will keep the pattern from warping or spring- 
ing out of shape if the stuff is dry — it will not be so well 
for working off when built as I have said it should be, 
but it will be right when done, which is the most im- 
portant. 

The radius pieces are let in flush with the top of the 
pattern, so that they do not interfere with the moulder 
when he is leveling and sleeking off the top of the mould 
around the teeth. It is not customary to let these pieces 
in, as show^n ; but I think it better to do so, for the 
reason just given. On the end is an iron plate, D, that 
fits against the spindle ; this plate has four slot holes in 
it for adjusting the segment pattern to the correct 
diameter. 

Referring to Fig. 190, it will be seen that a part of the 
segment on eaeh end is plain, having two lines, A and B, 
marked on the upper edge ; these lines are the centres 
of spaces between the teeth. It is desired to make the 
wheel i}^" larger in diameter one way than the other; 
this will allow y^" for planing the joint, and for splitting 
cores i" thick. In this case it is best to use cores for 
splitting, in preference to cast iron plates, as the iron 
plates would chill the surface to be planed, making it 
hard, and thus causing the planer hand trouble. Sup- 
pose this gear to have ninety-six teeth. After forty- 
eight or one-half of the teeth have been formed, two 
centre lines, \j4" apart, should be made on the top of 



PATTERN MAKING. IO3 

the mould, as shown, representing the joint of casting 
after it has been planed. Now by moving the spindle 
1^2" ^t right angles to these lines, and setting the line 
A, marked on the pattern, to the second centre line, it 
will give the necessary space between the teeth next the 
joint, allowing for \" splitting core, and y^" for planing. 

It will be noticed that on the end of the spindle is a 
square base C, into which two holes are cast for bolting 
it to a timber. These holes are slotted, enabling the 
moulder to move the center as described. The spindle 
is cored out like a pipe, and if bored a little tapering may 
be used as a socket for an ordinary spindle to work in. 
Such a spindle will be found a very handy, though 
simple, rig for making w^heels in halves, when joints have 
V) be planed. 

I have said that the hub is cut entirely through ; this 
should always be done, w^hether the halves are to be 
planed or not, as it relieves the shrinking strain in the 
arms and rim. 

The inside of the rim and the arms of the wheel are 
formed with cores. Boxes from which these cores are 
made as shown in Figs. 191 and 192. A half section of 
the arm, which is a cross shape section, is seen at E, and 
as in the case of oval section arms, a core box for one- 
half of the arm is all that is required. There are three 
loose pieces fitted in the end of the box to form the hub, 
one marked F, another the opposite hand to F, and the 
plain piece marked G shown outside the arm box. Each 
of these pieces matches the rib of arm at a. The two 
short sides b and c of the box are set Vj^" back from the 
radial line, or where the cores join, and two loose pieces 



104 



FA TTERN MAKING. 



The object of this is to give y^" stock on the hub, for 
planing. 

When F is used, the y^" piece on side b is left out, 
while the one on side c remains in, and when the oppo- 
site part to F \^ used, then the y^" piece on side c is left 
out, and the one for side b is put in. When G is used, 
then the y^" pieces go in on both sides. 

There being eight arms to this gear wheel, there will 
be four cores each when using F^ and the piece which is 
the opposite hand to F, and eight with G, making sixteen 
for the bottom and top. 

When these arm cores are located inside the mould 
whose diameter, it will be remembered, is made ly^" 
longer one way than the other, the cores at the hub will 
be \" apart, as seen in Fig. 193 ; this space will receive 
the splitting core after the two half-round cores for the 
bore have been set in place. 

The core box, from which the cores are made to form 
the inside of the rim between the arms, is shown in Fig. 
192. //"is the lug for bolting the wheel together at the 
rim, and is taken out after making four short cores. 
These cores, of course, are located in the mould, so that 
the lugs correspond with split in the hub, and when set 
will leave a space to receive the splitting core in the same 
way as the arm cores at the center in Fig. 193. The lug 
//being set y^" past the center line d shows the stock 
that is allowed for planing the joint. 

The two ends L and K of this box run under, making 
a " back draft," as represented by dotted lines on the 
side ; they are made thus, so that the ends of cores may 



PA7TERX MAKING. JO5 

fit against the sides of the arm cores. These ends being 
"back draft " are, therefore, made loose, in order that tlic 
cores may leave the box without taking it apart — the 
ends come out with the core. 

That part of the rim at the lugs is not cut into by the' 
splitting cores; the rim is, therefore, the full thickness at 
that point. This is done to prevent the wheel from 
breaking at the joint, and the ends from springing away 
from the center lines while shrinking, and that the cast- 
ing might remain intact for testing and laying out the 
two center lines. 

Having once made two gears 10 ft. 2]/.^" diameter, 
\" pitch, \2" face, in the manner described here, I had 
some misgiving that the rims might spring after they had 
been cut in two, causing the teeth next the joint to be 
out of place, but they did not, and after they were planed 
and bolted together the spaces between the teeth at the 
joint did not vary from the others. The wheels, also, 
were practically true, thus showing that with extra care 
on the part of moulder and pattern maker, a good job may 
be done in making gears this way and without the gear 
moulding machine. I do not mean by this to depreciate 
in any way gear moulding machines, but then they are 
not on hand in most shops when needed. 



Table of tJie Diat/ictrr of Wheels at the Pitch Cinle. from ji to joo I'l-eth. 



Sri! 



Pitch of the Teeth. 



inch. 



inch. 



6', 
6f 

7f 
7f 
8* 
9 

9l 
o lo 
o io| 

O III 

O II| 

o| 

Ij 

2 

2\ 

3 

3f 

4| 

4j 

5f 

54 

6J 

7 

7^ 



9i 

9f 

I of 

io# 

2 O 
2 o\ 
2 l' 

2 l|- 

2 I-l 

2 2j 

2 

2 

2 

2 

2 

2 

2 

2 

2 



7^ 



o 7^ 

o 8^ 

o 9 

o 9[ 

o lo] 



O Ilf 

o 
o,\ 

Is 

1 1 

o3 

21 
25 

3^ 

4ir 
4l 
51 
6 

6| 
7i 
7i 
8i 
9 

9l 
10 
io| 

If 

2i 
2 s 
3] 

4 

4l 
51 
5s 
61 

7I 
7f 
8i 
8i 
9l 
! 2 10 



inches, inches, inches. 



7 

7f 
81 
9 

9f 
o \o\ 
o io| 

O 11^ 

of 

T 1 

1 2 

2 

2t 

3l 
3l 
4i 
5i 
51 
6J 
7^ 
71 
8f 
9 

9f 
\o\ 

lOi 



7^ 

8J- 
8^ 
9\ 

[Ol 
O lOi 

o 112 

o| 

ll 
2I 

2| 

3* 
4i 
4l 
5J 
6i 
6| 
7f 
8i 
9 

98 

I of 
II 

III 

of 

I 



2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 9i 

2 10^ 

2 II 

2 114 

3 oi 



2 

2 
2 

2 
2 
2 
2 
2 
2 
2 
2 
2 

2 91 
2 loj 

2 III 

2 iii 

I 3 oi 

1^ :i 



9j 
10] 
II 

o| 
I 

2 

2* 

3t 

4 

4| 

51 

6 

6i 

7J 



lot 
II 

III 
oj 

i! 
2 

2| 
32 
45 

4^- 
100 



inches, inches. 



^4 

9l 
lOil 
"1 

o 

o| 

a 

2i 
3^ 
4 

4f 
5* 
6| 
7^ 
8 

8| 

9I 
10] 

11^ 

o 

o| 

2i 

3 

3* 

4l 

5? 

6i 

7 

7ff 



loi 



9t 



o 9¥ 
O IO| 
O Hi 

o| 

li 



Ilg 

2 oi 



Is 

2} 

3l 
4 
4i 
5l 
6f 
1\ 
8f 
9i 
2 io| 
2 lof 

2 III 

3 o| 
3 If 
3 2j 
3 3i 



3 7t 
3 8f 
3 9* 
3 105 

3 II 

4 oj 
4 I 
4 I5 



inches, inches. 
3- 3>^- 



O lof 

O IIJ 



4i 
5} 
6] 

7.^ 

n 

9 

10 

io| 

III 

Or 
l" 



2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 I 

2 I 

3 
3 
3 
3 
3 
3 
3 
3 

3 71 
3 
3 



81 
9I 
3 loi 

:; Ha 



O Ilf 

o| 

If 

2^- 

32 
4^ 
5^ 

6| 
7f 
8| 



io| 
114 



04- 
I4- 

2^ 

4l 
5l 
6| 
7l 
81 
9i 

3 10* 

3 

4 

4 

4 

4 

4 

4 

4 

4 

4 

4 

4 



Table of the J)i(i///i'/rr of Wheels af the Pitch Circle — Continued. 



«:Si - 














Pitch of the Teeth 










"E^! inch. 


inch. 


inches. 


inches. 


inches. 


inches. 


inches. 


inches. 


inches. 


' inches. 




i^. 


] 


%■ 




.. I ^ 


^>A- 


^%. 


=K- 


2%. 


3- 


3M- 


1 Sh- 


58 


' ?i 


2 


IO§ 


3 


1 
Os |3 


31 


3 51 


3 10^ 


4 2:1 


4 7f 


5 


is 4i 


59 


2 H 


2 


11; 


3 


U 


3 


4 


3 65 


3 la 


4 3l 


4 8^ 


5 I 


:5 5? 


60 


2 9f 


2 


il; 


3 


2.1 


3 


4| 


3 7 


3 III 


4 4^ 


4 91 


5 2 


5 6i 


61 


2 10 


3 


0^ 


3 


2i 


3 


51 


■^ Zf 


4 0^ 


4 5:1 


4 lol 


5 3l 


5 8 


62 


2 10^ 


3 


I 


3 


J) 2 


3 


6 


3 8^ 


4 If 


4 6| 


4 "1 


5 4l 


5 9 


63 


2 II 


3 


l| 


3 


4^ 


3 


61 


3 9i 


4 2| 


4 7^ 


5 oi 


5 51 


5 loi 


64 


2 III 


3 


2| 


3 


4l 


3 


7l 


3 9l 


4 3 


4 8 


5 i^ 


5 6} 


5 11^^ 


65 


3 0; 


3 


2\ 


3 


5i 


3 


8 


3 10^ 


4 3l 


4 8| 


5 2 


5 71 


6 o- 


66 


3 of 


3 


3f 


3 


6 


3 


8| 


3 III 


4 42 


4 9l 


5 3 


5 81 


6 I.' 


67 


3 't 


3 


4^ 


3 


6^ 


3 


9l 


4 


4 5l 


410I 


5 4 


5 9| 


6 2^ 


68 


3 If 


3 


4l 


3 


7d 


3 


10 


4 of 


4 6^ 


4 Ilr 


5 5 




6 3il 


69 


3 2f 


3 


5J 


3 


r? 


3 


io| 


4 i^ 


4 7 


5 0^ 


5 6 


5 III 


6 4-i 


70 


3 3 


3 


5l 


3 


8* 


3 


III 


4 2^ 


4 7l 


5 I 


5 61 


6 0^ 


6 6 


71 


3 3j 


3 


6| 


3 


9i 


4 





4 2| 


4 8^ 


5 2, 


5 71 


6 i^ 


6 7 


72 


3 4i 


3 


6f 


3 


9l 


4 


o| 


4 3^ 


4 9f 


5 3 


5 8| 


6 2j 


6 8| 


73 


3 4f 


3 


7i 


3 


10^ 


4 


if 


4 4l 


4 10 


5 3i 


5 9^ 


6 3i 


6 9ii 


74 


3 5i 


3 


7l 


3 


III 


4 


2 


4 5 


4 loi 


5 4l 


5 10 


6 4^ 


6 lof 


75 


3 5l 


3 


8| 


3 


1I4 


4 


2| 


4 5l 


4 iif 


5 5f 


5 ii| 


6 5i 


6 lU 


7^> 


3 6f 


3 


9f 


4 


of 


4 


3l 


4 6^ 


5 o| 


5 6^ 


6 0.1 


6 6f 


7 of 


77 3 61 


3 


9\ 


4 


I 


4 


4 


4 7l 


5 il 


5 7f 


6 i|- 


6 7f 


7 II 


78 


3 Ih 


3 


10* 


4 


if 


4 


4l 


4 7l 


5 2 


5 H 


6 2^ 


6 8f 


7 2i 


79 


3 i 


3 


iii 


4 


2I 


4 


5? 


4 8^ 


5 2| 


5 9i 


6 3^ 


6 9f 


7 4 


80 


3 8J 


3 


iif 


4 


3 


4 


6J 


4 91 


5 31 


5 10 


6 4f 


6 lof 


7 51 


81 


3 9^ 


4 


o§ 


4 


3l 


4 


6| 


4 10 


5 4^ 


5 iof 


6 5i 


6 lU 


7 6] 


82 


3 9' 


4 


o| 


4 


41^ 


4 


7^ 


4 lof 


5 5l 


5 iif 


6 6| 


7 oi 


7 7f 


83 


3 104 


4 


I* 


4 


4i 


4 


8i 


411J 


5 6 


6 of 


6 7^ 


7 If 


7 8| 


84 


3 io| 


4 


2i 


4 


5? 


4 


81 


5 oi 


5 6« 


6 li 


6 8| 


7 2f 


7 9| 


85 


3 11} 


4 


2| 


4 


6^ 


4 


9f 


5 o| 


5 7l 


6 2f 


6 9l 


7 3f 




86 


3 iif 


4 


3^ 


4 


6f 


4 


loi 


5 If 


5 8. 


6 3l 


6 lo.i 


7 5 


7 "1 


87 


4 oj 


4 


3f 


4 


7I 


4 


lOs 


5 2I 


5 9i 


6 4^ 


6 11" 


7 6 


8 oi 


88 


4 I 


4 


4? 


4 


8 


4 


iii 


5 3 


5 10 


6 5 


7 


7 7 


8 2 


89 


4 li 


4 


5l 


4 


8f 


5 


°f 


5 3l- 


5 io| 


6 51- 


7 I 


7 8 


8 3l 


90 


4 2i 


4 


5l 


4 


94 


5 


o| 


5 4l 


5 iif 


6 6| 


7 2 


7 9i 


8 4l 


91 


4 2| 


4 


6i 


4 


9I 


5 


ll 


5 5^ 


6 of 


6 7i 


7 2I 


7 loj 


8 5i 


92 


4 3i 


4 


7 


4 


loi 


5 


2i 


5 5l 


6 I 


6 8.^ 


7 3l 


7 III 


8 6^ 


93 


4 3l 


4 


7l 


4 


iii 


5 


2I 


5 6f 


6 2 


6 9f 


7 4^ 


8 ol 


8 7f 


94 


4 4I 


4 


8J 


4 


114 


5 


3* 


5 7f 


6 2| 


6 lol 


7 5l 


8 li 


8 8| 


95 


4 4I 


4 


8| 


5 


Oj 


5 


4I 


5 8 


6 3J 


6 III 


7 6| 


8 2I 


8 9f 


96 


4 5? 


4 


9I 


5 


Ij 


5 


5, 


5 8| 


6 4f 


7 


^ if 


8 3f 


8 io| 


97 


4 6 


4 


10 


5 


ll 


5 


5t 


5 9^ 


6 5i 


7 oi 


8 4f 


9 


98 


4 61 


4 


10^ 


5 


2| 


5 


6i 


5 loi 


6 6 


7 if 


7 9i 


8 5f 


9 I* 


99 


4 7^ 


4 


II 


5 


3 


5 


7 


5 II 


6 6| 


7 2f 


7 10^ 


8 60^ 


9 2i 


100 


4 7f 


4 


III 


5 


35 


5 


7t 


5 III 


6 7i 


7 3l 


7 iij 


8 7I 


9 3l 


101 


4 8^ 


5 


o\ 


5 


44 


5 


81 


6 oi 


6 8f 


7 4l 


8 0^ 


8 8^ 


9 4j 


102 


4 8| 


5 


I 


5 


5 


5 


9 


6 I 


6 9i 


7 5i 


8 i| 


8 9I 


9 5f 


103 


4 9I 


5 


l4 


5 


5' 


5 


9f 


6 ij 


6 10 


7 6J 


8 2} 


8 loi 


9 6f 


104 


4 10 


5 


I4 


5 


61 


5 


10} 


6 21 


6 lof 


7 7 


8 31 1 


8 11* 


9 7f 



Table of the Diiniietcr of ll'Jieels at the Pitch Circle — Continued. 



S-5 


















Pitch of the Teeth 
















ji u 


inch. 


inch. 


inches. 


inc 


,hes. 


inches. 


inches. 


inches. 


inches. 


inches. 


inches 


3H 


I 


>i 


I 


^4 




2. 


2 


1/ 


-%■ 


2>^- 


2%. 




J- 


3H- 


3y2. 


105 


4 


io| 


5 


2| 


5 


64^ 


5 


II 


6 3 


6 ii.i 




li 


8 


41 


9 


of 


9 8 


106 


4 


II 


5 


2i 


S 


7i 


S 


III 


6 3t 


7 oi 




8f 


8 


Si 


9 


i| 


9 10 


107 


4 


III 


5 


35 


S 


8^ 


6 


Of 


6 4i 


7 i^ 




9l 


8 


6i 


9 


2f 


9 II 


108 


5 


Og 


5 


4^ 


5 


8| 


6 


I 


6 S 


7 2 




loi 


8 


7* 


9 


3l 


10 


109 


5 


of 


5 


4| 


s 


9l 


6 


II 


6 51 


7 2f 




III 


8 


8 


9 


4f 


10 I 


no 


5 


u 


5 


Si- 


5 


10 


6 


2| 


6 6^ 


7 3^ 


8 


0} 


8 


9 


9 


Si 


10 2 


III 


5 


ll 


5 


si 


5 


io| 


6 


3 


6 7I 


7 4i 


8 


i| 


8 


10 


9 


6^ 


10 3 


112 


5 


2| 


5 


61 


S 


III 


6 


3l 


6 8 


7 Si 


8 


2 


8 


IO| 


9 


7^- 


10 4 


113 


5 


3 


5 


7 


6 





6 


4f 


6 8t 


7 6 


8 


3 


8 


ii| 


9 


8| 


10 6 


114 


5 


3i 


5 


7l 


6 


o\ 


6 


S^ 


6 9t 


7 6| 


8 


3l 


9 


of 


9 


9^ 


10 7 


115 


5 


4 


5 


81- 


6 


It 


6 


Sl 


6 10 


7 7* 


8 


4l 


9 


ll 


9 


loi 


10 8 


116 


5 


4f 


5 


81 


6 


I4 


6 


6| 


6 io| 


7 81 


8 


S* 


9 


2f 


10 





10 9 


117 


5 


5l 


5 


9J 


6 


2j 


6 


n 


6 11^ 


7 9* 


8 


6f 


9 


38 


10 


I 


10 10 


118 


5 


5l 


5 


10 


6 


3I 


6 


71 


7 oj 


7 10 


8 


74 


9 


4i 


10 


2 


10 II 


119 


5 


6J 


5 


I of 


6 


3l 


6 


8i 


7 I 


7 io| 


8 


8g 


9 


s* 


10 


3^ 


II 


120 


5 


6| 


5 


11} 


6 


4l 


6 


9J 


7 If 


7 III 


8 


9 


9 


6.; 


10 


4l 


II I 


121 


5 


7l 


5 


lU 


6 


5 


6 


9l 


7 2I 


8 0} 


8 


9i 


9 


7l 


10 


Si 


II 2 


122 


5 


8 


6 


0^ 


6 


sl 


6 


\o\ 


7 3 


8 I 


8 


I of 


9 


8J 


10 


6^ 


II 3 


123 


5 


8^ 


6 


I 


6 


6i 


6 


\\\ 


7 3l 


I n 


8 


iif 


9 


9i 


10 


7l 


II S 


124 


5 


9 


6 


i| 


6 


7 


6 


III- 


7 42 


8 2f 


9 


oh 


9 


lOr^ 


10 


8i 


II 6 


125 


5 


9l 


6 


2I- 


6 


7i 




05 


7 SJ 


? ^^' 


9 


ll 


9 


TT 1 


10 


9f 


II 7 


126 


5 


10^ 


6 


2| 


6 


8^ 




li 


7 6 


8 44 


9 


24 


10 


O4 


10 


I of 


II 8 


127 


5 


loj 


6 


3I 


6 


8f 




2 


7 6f 


^ 5, 


9 


3l 


ro 


I4 


10 


III 


II 9 


128 


5 


III 


6 


4 


6 


9\ 




2J 


7 7i 


8 5i 


9 


4 


10 


2i 


II 


oi 


II 10 


129 


5 


Hi 


6 


4^ 


6 


loi 




3i 


7 8 


8 6f 


9 


48 


10 


3l' 


II 


ij 


II II 


130 


6 


of 


6 


SJ 


6 


io| 




4 


7 8f 


8 7.i 


9 


sl 


10 


4l 


II 


2i 


12 


131 


6 


I 


6 


St 


6 


iif 




4* 


7 9i 


8 81- 


9 


6- 


10 


5 


II 


3l 


12 2 


132 


6 


i^ 


6 


61 









^* 


7 loi 


f ^3 


9 


1 


10 


6 


II 


4i 


12 3 


133 


6 


2 


6 


7 




of 




6 


7 io| 


8 9I 


9 


81 


10 


7 


II 


Sl 


12 4 


134 


6 


2f 


6 


7i 




li 




6f 


7 11* 


8 lof 


9 


94 


10 


8 


II 


6f 


12 5 


135 


6 


3k 


6 


8* 




2 




7i 


8 oi 


8 iif 


9 


I Ok 


10 


8| 


II 


7l 


12 6 


136 


6 


3f 


6 


8| 




2^ 




8 


8 I 


9 oi 


9 


II 


10 


9l 


II 


8f 


12 7 


137 


6 


4i 


6 


9t 




31- 




8f 


8 If 


9 I 


10 





10 


I of 


II 


93 


12 8 


138 


6 


4f 


6 


10 




3l 




9i 


8 2\ 


9 If 


10 


o| 


10 


iif 


II 


lof 


12 9 


139 


6 


Sit 


6 


loi 




^\ 




10 


8 3i 


9 2f 


10 


if 


II 


of 


II 


III 


12 10 


140 


6 


6 


6 


ii| 




5^ 




I of 


8 3i 


9 3f 


10 


2* 


II 


if 


12 


oi 


13 


141 


6 


6^ 


6 


III 




Sl 




iif 


8 4j 


9 4i 


10 


3i 


II 


2h 


12 


ll 


13 I 


142 


6 


7 




ol- 




6| 


8 





8 Si 


9 S 


10 


4t 


II 


sl 


12 


2|- 


13 2 


143 


6 


7f 




o| 




7 


8 


of 


8 6 


9 Sl 


10 


Ss 


II 


4h 


12 


3i 


13 3 


144 


6 


8i 




I* 




7l 


8 


If 


8 6| 


9 6 


10 


6 


II 


Sl 


12 


4l 


13 4 


145 


6 


8| 




2 




8i 


8 


2 


8 71 


9 7| 


10 


6i 


II 


6h 


12 


6 


'3 1 


146 


6 


9i 




2| 




9 


8 


2| 


8 8^ 


9 8J 


10 


7|ii 


7l 


12 


7 


13 6 


147 


6 


9l 




3l 




9\ 


8 


3l 


8 81 


9 9 


10 


8^11 


8i 


12 


8 


'^ ? 


148 


6 


10* 




3i 




\o\ 


8 


4^ 


8 9J 


9 9l 


10 


9* II 


9t 


12 


9l 


13 8 


149 


6 


II 




4* 




I of 


8 


4i 


8 loi 


9 10^ 


10 


lofii 


loJ 


12 


loi 


13 10 


ISO 


6 


II* 




S 




iii 


8 


S* 


8 n 


9 III 


10 


II X 


II 


11.1 


12 


III 


13 II 



[08 



Table of the Diameter of Wheels at the Fitch Circle — Continued. 











Pitch of the Teeth. 








Number of 
Teeth. 






















inches. 


inches. 


inches. 


inches. 


inches. 


inches. 




2^ 


2H- 


2%. 


3 


- 


3>i- 


3>^ 


151 


9 


oi 


10 oj 


II 


o| 


12 


o\ 


13 


oj 


14 Oi 


152 


9 


0^ 


10 0; 


II 


I 


12 


li 


13 


li 


14 I| 


153 


9 


it 


10 v\ 


II 


i; 


12 


2 


13 


24 


14 2| 


154 


9 


2| 


10 2i 


II 


2^ 


12 


3 


13 


3l 


14 3i 


155 


9 


3 


10 3i 


II 


3g 


12 


4 


13 


4l 


14 4g 


156 


9 


3l 


10 4i 


II 


^\ 


12 


4| 


13 


51 


14 5-1 


157 


9 


4| 


10 4t 


II 


s% 


12 


5i 


13 


6| 


14 6| 


158 


9 


5i 


10 5t 


II 


6| 


12 


6t 


13 


7| 


14 8 


^-59 , 


9 


5; 


10 6.^ 


II 


l\ 


12 


I'h 


13 


"8 


14 9\ 


160 


9 


6J 


10 7| 


II 


8 


12 


8| 


13 


9^ 


14 loi 


161 


9 


7| 


10 8| 


II 


8^ 


12 


9t 


13 


loi 


14 Hi 


162 


9 


8 


10 8^ 


II 


9i 


12 


lof 


13 


11^ 


15 of 


163 


9 


8| 


10 91 


II 


io| 


12 


iif 


14 


of 


15 If 


164 


9 


9l 


10 loi 


II 


Ml 


13 


Oi 


14 




15 2| 


165 


9 


10 J 


10 ii| 


12 


of 


13 


u 


14 


2I 


15 3l 


166 


9 


lOi 


II 


12 


li 


13 


2I 


14 


3I 


15 44 


167 


9 


III 


II 0; 


12 


2i 


13 


3l 


14 


4l 


15 6 


168 


lo 


o| 


II If 


12 


3 


13 


4f 


14 


5^ 


15 7i 


169 


lo 


I 


II 2i 


12 


3| 


13 


51 


14 


6| 


15 8i 


170 


lo 


I 4 


II •>\ 


12 


44 


13 


6| 


14 


7l 


15 9t 


171 


10 


2g 


II 4 


12 


5f 


13 


7 


14 


8J 


15 io| 


172 


10 


3i 


II 4i 


12 


6i 


13 


8 


14 


9? 


15 "1 


173 


10 


3i 


II 5i 


12 


7f 


13 


9i 


14 


104 


16 o| 


174 


10 


4^ 


II 6| 


12 


8i 


13 


10 


15 





16 li 


175 


10 


51 


II 1\ 


12 


9i 


13 


II 


15 


li 


16 2; 


176 


10 


6 


II 8 


12 


10 


14 





15 


2I 


16 4 


177 


10 


6| 


II 8i 


12 


lOi 


14 


I 


15 


3i 


16 si 


178 


lo 


7f 


II 9t 


12 


Hi 


14 


It 


15 


4i 


16 6f 


179 


10 


8i 


II lof 


13 


0^ 


14 


2| 


15 


5i 


16 7l 


180 


10 


81 


II \\\ 


13 


, i 


14 


3? 


15 


^1 


16 8| 
16 9l 


181 


10 


91 


12 


13 


2^ 


14 


45 


15 


7i 


182 


10 


io| 


12 o| 


13 


3i 


14 


5| 


15 


8i 


i6 lof 


183 


10 


II 


12 if 


13 


4i 


14 


^f 


15 


9t 


16 iH 


184 


10 


iif 


12 2| 


13 


5 


14 


7t 


15 


I of 


17 oi 


185 


II 


o| 


12 3i 


13 


Si 


14 


8| 


15 


III 


17 2* 


186 


II 


ll 


12 4 


13 


6^ 


14 


9! 


16 


of 


17 3i 


187 


II 


li 


12 4| 


13 


7l 


14 


lOi 


16 


II 


17 4| 


188 


II 


2-^ 


12 51 


13 


8^ 


14 


iii 


16 


2| 


17 5t 


1S9 


II 


31 


12 6| 


13 


9I 


15 


o| 


16 


3^ 


17 6r 


190 


II 


4 


12 ll 


13 


io| 


15 


li 


16 


Ah 


17 7 


191 


II 


4| 


12 7i 


13 


ii| 


15 


21 


16 


Sh 


17 » 
17 9{ 


192 


II 


5I 


12 8| 


14 





15 


3^ 


16 


6| 


193 


II 


6i 


12 9i 


14 


Oi 


15 


4i 


16 


7t 


17 II 


194 


II 


6i 


12 10^ 


14 


Ij 


15 


5J 


16 


81 


18 oi 


15 


1 1 


71' 


12 iij 


14 


5 

- 1 


'5 


6i 


16 


91 


18 i\ 



109 



Table of the Diameter of Wheels at the Pitch Circle — Continued. 













Pitch of the Teeth. 








Number of 
Teeth. 
























inches. 


inches. 


inches. 


inches. 


inches. 


linches. 




2 


^• 


2^ 


^• 


2%. 




5- 


3}i- 


3^. 


196 


II 


8f 


12 


il| 


14 


z\ 


15 


7i 


16 


io| 


18 2f 


197 


II 


9 


13 


of 


14 


4i 


15 


8^ 


16 


Iif 


18 3i 


198 


II 


9f 


13 


i^ 


14 


51 


15 


9 


17 


o| 


18 4^] 


199 


II 


loi 


13 


2f 


14 


6^ 


15 


10 


17 


li 


'! 1^ 


200 


II 


I a 


13 


3i 


14 


7 


15 


lof 


17 


2| 


'! ^1 


201 


II 


\\\ 


13 


3l 


14 


7i 


15 


iii 


17 


3i 


18 7i 


202 


12 


of 


13 


4f 


14 


81 


16 


o| 


17 


U 


18 9 


203 


12 


if 


13 


51 


14 


9t 


16 


li 


17 


6 


18 10 


204 


12 


2 


13 


61 


14 


loi 


16 


2i 


17 


7 


18 11^ 


205 


12 


2i 


13 


7J 


14 


III 


16 


3I 


17 


8 


19 0] 


206 


12 


l\ 


13 


7i- 


15 


of 


16 


4f 


17 


9* 


19 n 


207 


12 


4t 


13 


8f 


15 


li 


16 


5f 


17 


io| 


19 2), 


208 


12 


4i 


13 


9I 


15 


2 


16 


6| 


17 


II* 


19 3I 


209 


12 


5f 


13 


10} 


15 


-2.1 


16 


7* 


18 


04^ 


19 4f 


210 


12 




13 


Hi 


15 


3i 


16 


8i 


18 


li 


19 5-s 


211 


12 


7I 


13 


H| 


15 


4f 


16 


9l 


18 


2? 


19 7 


212 


12 


7l 


14 


of 


15 


52 


16 


I of 


18 


3i 


19 8^ 


213 


12 


8^ 


14 


'f 


15 


61 


16 


iif 


18 


4f 


19 94 


214 


12 


9: 


14 


2^ 


15 


7i 


17 


of 


18 


Sf 


19 10- 


215 


12 


9I 


14 


3 


15 


8^ 


17 


If 


18 


6f 


19 II r 


216 


12 


io| 


14 


3l 


15 


9, 


17 


2| 


18 


7f 


20 


217 


12 


"1 


14 


4f 


15 


9l 


17 


3f 


18 


81 


20 l\ 


218 


13 





14 


51 


15 


io| 


17 


4i 


18 


9i 


20 2y 


219 


13 


o| 


14 


6i 


15 


II 1 


17 


5b 


18 


io| 


20 4 


220 


13 


\\ 


14 


7 


16 


o| 


17 


6 


18 


112 


20 5i 


221 


13 


2j 


14 


7l 


16 


If 


17 


7. 


19 


o| 


20 6J 


222 


13 


2| 


14 


8f 


16 


2f 


17 


7i 


19 


if 


20 7f 


223 


13 


3t 


14 


9f 


16 


3i 


17 


8| 


19 


2i 


20 8J 


224 


13 


4g 


14 


io| 


16 


4, 


17 


9ff 


19 


34 


20 9f 


225 


13 


5? 


14 


II 


16 


4f 


17 


io| 


19 


4I 


20 I of 


226 


13 


5l 


14 


ii| 


16 


5-J 


17 


iif 


19 


5I 


20 ii|^ 


227 


13 


6^ 


15 


of 


16 


61 


18 




19 


6| 


21 o| 


228 


13 


7i 


15 


ll 


16 


7i 


18 


if 


19 


71 


21 2 


229 


13 


8 


15 


2i 


16 


81 


18 


2f 


19 


Si 


21 3l 


230 


13 


81 


15 


3 


16 


98 


18 


3f 


19 


9f 


21 4| 


231 


13 


9f 


15 


3f 


16 


loi 


18 


42 


19 


io| 


21 5f 


232 


13 


loi 


15 


4f 


16 


II 


18 


5? 


20 





21 6| 


233 


13 


I Of 


15 


5i 


16 


Hi 


18 


61 


20 


I 


21 72 


234 


13 


Ilj 


15 


6J 


17 


i 


18 


7§ 


20 


2 


21 8f 


235 


14 


0^ 


15 


7 


17 


if 


18 


8f 


20 


3 


21 9i 


236 


14 


I 


15 


7i 


17 


22 


18 


9f 


20 


4i 


21 io| 


237 


14 


If 


15 


8^ 


17 


3s 


18 


lof 


20 


5* 


22 


238 


14 


2f 


15 


10? 


17 


4f 


18 


iii 


20 


61 


22 ij 


239 


14 


3^ 


15 




17 


5i 


19 


oi 


20 


7l 


22 2I 


240 


14 


3l 


15 


loi 


17 


6 


19 


a 


20 


H 


22 3I 



IIO 



Table of the Diameter of Wlicrh <it //ir Pilih Circle — ('onlinued. 



Number of 
Teeth. 



241 

242 

243 
244 

245 
246 

247 
248 
249 
250 

251 
252 

253 
254 
255 
256 

257 
258 

259 
260 
261 
262 
263 
264 
265 
266 
267 
268 
269 
270 
271 
272 
273 
274 
275 
276 
277 
278 

279 
280 
281 
282 
283 
284 
285 



inches. 
^^4 



I 7 

21 

3-;i 
4 

4:1 
6i 

1% 



14 10^ 
14 u 

14 11-^ 
15 
15 
i5 
15 
15 
15 
15 
15 
15 
15 
15 

15 9 

15 9i 

15 lof 

15 III 

15 "I 

16 of 

r6 T^ 
to Ig 

16 2 

16 2\ 

16 

16 

16 

16 

16 

16 

16 

16 

16 

16 

i6 

16 

17 



32 

4l 

4^ 

51 

6| 

7 

7l 



9 b 

[Of 

'If 



inclu-.^ 



15 "8 

16 o4 
16 r^ 
16 2l 
16 2^ 
16 3:{ 
1 6 4.', 



16 5A 
16 6^ 



6i 
7h 
8.', 

9] 



I'it.l. orihf:'IV--lh. 
inches. 



16 loj 
16 10^ 

16 iiA 

17 o^ 

17 I« 



17 
17 
17 
17 
17 
17 

17 7 

17 8 

17 9 

17 10 

17 10 

17 Hi I 



[8 



5 

8 
Of I 

I 8 

2 

2I 



4§ 
51 
6 

18 7^ 



98 
98 



inc 


,es. 


..*..! 


17 


6^ 


17 


7^ 


17 


8^ 


17 


92 


17 


io| 


17 


1 1 11 


18 


oA 


18 




18 


I^ 


18 


A 


18 


3i 


18 


4^ 


18 


5^ 


18 


6| 


18 


n 


18 


8 


18 


8^ 


18 


98 


i8 


loj 


18 


III 


19 


ojl 


19 


I ■' 


19 


28 


19 


3 


19 


38 


19 


4s , 


19 


5l 


19 


6^ 


19 


7t 


19 


81 1 


19 


9I 


19 


10 j 


19 


lOf 


19 


11^ 1 


20 


of i 


20 


i^ 


20 


2f 


20 


3i 


20 


48 


20 


5 


20 


5 s 


20 


6-^ 


20 


7f 


20 


%\ 


20 


9f 



19 2^ 

19 3h 

19 4^ 

19 5'i 

19 6'^ 

19 7il 



19 98 

19 lOft 

19 Hi 

20 of 

20 \\ 
20 2I 
20 3I 

20 4t 
20 58 
20 6 1 

20 ni 

20 8] 
20 9I 
20 lO^ 

20 \\\ 

21 ol 



2 

2| 

3| 
4i 
5i 
6| 

7f 

8f 

9i 

lof 



22 o^ 

22 l| 

22 2f 

22 3f 

22 4| 

I 22 5] 

22 6^ 

22 ll 



inches. inches. 

3M- -iVi 



20 9| 
20 10^ 

20 ii| 

21 oi 



6f 

7i 

8f 
9l 



21 i^ 

21 2I 

21 Z\ 

21 4^ 

21 52 

21 

21 

2] 
21 

21 Io| 

21 I if 

22 o| 
22 l| 
22 2I 
22 3I 
22 4^ 
22 6 
22 7 
22 8 
22 9I 
22 lO^ 
22 III 



23 o\ 

23 1 4 

23 2i 

23 3l 

23 4f 

'^ If 

23 6i 

23 7l 

23 81 

23 92 

23 10^ 
25 112 

24 of 

24 
24 

24 1% 



If i 

a 1 



24 4l 
24 54 
24 6^ 



22 4| 

22 5^ 

22 (i'l 

22 ll 

22 8? 

22 10 

22 Hi 

23 oi 
23 M 

23 2j 

23 3l 

23 4^ 

23 5^ 

23 6? 

23 8 

23 94 

23 lOg 

23 11^ 

24 o^ 

24 I 8 

24 2| 

24 38 

24 5 

24 6J 

24 7] 

24 ^l 

24 9 1 

24 10^ 

24 III 

25 o^ 

25 ll 

25 3 

25 4ii 

25 51 

25 61 

25 7i 

25 8| 

25 9l 

25 10 A 

25 11^ 

26 I 

26 2| 

26 35 

26 4| 

26 5^ 



Table of the Diame(er of Wheels at the Pitch Circle — Continued. 













Pitch of the Teeth. 








Number of 
Teeth. 






















inches. 


inch 


es. 


inches. 


inches. 


inches. 


inches. 




»H. 


-%• 


23/ 


/^. 


3- 


31/ • 


s'A. 


286 




oj 


. 18 


II* 


20 


I of 


22 9 


24 


n 


26 6f 


287 




^\ 


19 


Of 


20 


Ilf 


22 10 


24 


H 


26 7l 


288 




A 


19 


If 


21 





22 II 


24 


9i 


26 8| 


289 




2^ 


19 




21 


o| 


22 Il|- 


24 


loi 


26 9i 


290 




3l 


19 


2f 


21 


n 


23 o| 


25 





26 II 


291 




4t 


19 


32 


21 


2f 


23 li 


25 


I 


27 oi 


292 




5^ 


19 


4J 


21 


3f 


23 2i 


25 


2 


27 If 


293 


17 


5i 


19 


5* 


21 


4i 


23 3| 


25 


3i 


27 2f 


294 




6.V 


19 


5^ 


21 


5^ 


23 4t 


25 


4| 


27 3^ 


295 




7I 


19 


6| 


21 


6i 


23 51 


25 


5? 


27 4i 


296 




7i 


19 


1\ 


21 


7 


23 6| 


25 


6i 


27 5¥ 


297 




8f 


19 


8f 


21 


7i 


23 7f 


25 


7i 


27 6^: 


298 




9l 


19 


9^ 


21 


'8| 


23 8| 


25 


Si 


27 7- 


299 




loi 


19 


9^ 


21 


9f 


23 92 


25 


9l 


27 9^ 


300 




loi 


19 


io| 


21 


io| 


23 lOf 


25 


I of 


27 lO: 





might of 


Cast Iron 


Balls from 1 to 12 Inches Diameter 




Size. 


Wt. 


Size. 


Wt. 


Size. 


Wt. 


Size. 


Wt. 


Size. 


Wt. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


I 


.136 


3i 


SM 


6 


2945 


8^ 


83-73 


II 


181.48 


I^ 


.460 


4 


8.72 


^J 


37-44 


9 


99-4 


11^ 


207.37 


2 


1.09 


4* 


12.42 


7 


46.76 


9^- 


116. 9 


12 


235-62 


2^ 


2.13 


5 


17.04 


7^ 


57-52 


10 


136.35 






3 


3-68 


5+ 


22.68 


8 


69.81 


10^ 


157.84 







Weight of Cast Iron Pipes 12 Inches Long, from \ to \\ Inch Thick. 



Diam. Inch. 


Inch 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


of Bore. 1^ 


^ 


y^ 


% 


% 


% 


I 


-% 


iM 


Inch. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


I 


3.06 


5.06 


7-36 


9-97 


12.89 


16.II 


19.63 






li 


3.68 


5.98 


8.59 


11.51 


14-73 


18.25 


22.09 






IJ 


4.29 


6.9 


9.82 


13.04 


16.56 


20.4 


24-54 


28.99 


33-74 


I| 


4.91 


7-83 


11.05 


14-57 


18.41 


22.55 


27. 


31-75 


36-76 


2 


5-53 


8.75 


12.27 


16.11 


20.25 


24.7 


29-45 


34.46 


3989 


2i 


6.14 


9.66 


13-5 


17.64 


22.09 


26.84 


31-85 


37.28 


42.95 


2I 


6.74 


10.58 


14.72 


19.17 


23.92 


28.93 


34-36 


40.03 


46.02 


2f 


7.36 


II-5 


15-95 


20.7 


25-71 


31.14 


36-81 


42.8 


49-08 


3 


7.98 


12.43 


17.18 


22.19 


27.62 


33-29 


39.28 


45-56 


52.16 


3i 


8.59 


1334 


18-35 


23-78 


2945 


35-44 


41.72 


48.32 


55-22 


Z\ 


9.2 


14.21 


19.64 


25-31 


31-3 


37-58 


44.18 


51.08 


58.29 


l\ 


9.76 


15-19 


20.86 


26.85 


33-13 


39-73 


46.63 


53-84 


61.36 


4 10.44 


16.11 


22.1 


28.38 


34-98 


41.88 


49.09 


56.61 


64-43 


4i ll-l 


17.08 


23-37 


29.97 


36-87 


44.08 


51.6 


59-42 


67-55 


4.} 11.66 


17-94 


24.54 


31-44 


38.65 


46.17 


53-99 


62.12 


70.56 


44 12.27 


18.87 


25-77 


32.98 


40.5 


48.32 


56.45 


64.89 


73.63 


5 12.88 


19.78 


26.99 


34-51 


42.33 


50.46 


58.9 


67-64 


76.69 


54 13-5 


20.71 


28.23 


36-05 


44.18 


52.62 


61.36 


70.41 


79-77 


5^ I4-II 


21.63 


29-45 


37-58 


46.02 


54.76 


63.81 


73-17 82.84 


5l 


1473 


22.55 


30.68 


39.12 


47.86 


56.91 


66.27 


75-94 


85.91 



"3 



IFef^r/i/ 


of Cast Iron Pipes 12 


Inches Long, from \ to 


V\ Inch 


Thick- 


— Cont. 


Diam. 


Inch, 


Inch, 


Inch, 


Inch, 


Inch, 


Inch, 


Inch, 


Inch, 


Inch, 


'A Bore. 


M 


% 


3^ 


% 


%. 


% 


I 


i>^ 


^34 


Inch. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


6 


15-34 


23-47 


31-91 


40.65 


49-7 


59.06 


6873 


78.7 


88.75 


61- 


15-95 


24-39 


To-n 


42.18 


51-54 


61.21 


71.18 


81.23 


92.04 


6i 


16.57 


25-31 


34-36 


4372 


53-39 


63-36 


73-41 


84.22 


95-1 


4 


17.18 


26.23 


35-59 


45-26 


55-23 


65.28 


76.09 


86.97 


98.18 




17.79 


27-15 


36.82 


46.79 


56.84 


67.65 


78.53 


89-74 


101.24 




18.41 


28.08 


38.05 


48.1 


58.91 


69-79 


81. 


92-5 


104.31 




19.03 


29. 


39-05 


49-86 


60.74 


71-95 


83-45 


95.26 


107.38 




19.64 


29.69 


40-5 


51-38 


62.59 


74.09 


85.9 


98.02 


110.45 




20.02 


30.83 


41.71 


52-92 


64.42 


76.23 


88.35 


100.78 


"|-5J 


H 


20.86 


31-74 


42.95 


54-45 


66.26 


78.38 


90.81 


103-54 


116.58 


H 


21.69 


329 


44-4 


56.21 


68.33 


80.76 


93-49 


106.53 


119.87 


8| 


22.09 


33-59 


45-4 


57-52 


69-95 


82.68 


95-72 


109.06 


122.72 


9 


22.71 


3452 


46.64 


5907 


71.8 


84.84 


98.18 


1 1 1.84 


125.8 


9\ 


23-31 


35-43 


47-86 


60.59 


73-63 


86.97 


100.63 


114-59 


128.85 


92 


23-93 


36-36 


49.09 


62.13 


75-47 


89-13 


103.09 


117-35 


131-93 


9l 


24-55 


37-28 


50.32 


63.66 


77-32 


91.28 


105.54 


120.12 


134-99 


lO 


25.16 


38.2 


51-54 


65.2 


79.16 


93-42 


108. 


122.87 


138.06 


loj 


25-77 


39-11 


52.77 


66.73 


80.99 


95-57 


110.44 


125-63 


141. 12 


loj 


26.38 


40.04 


54- 


68.26 


82.84 


97.71 


112. 9 


128.39 


144.19 


I of 


27- 


40.96 


55-22 


69.8 


84.67 


99.86 


115-35 


131-15 


147-26 


II 


27.62 




56.46 


71-33 


86.52 


102.01 


117.81 


133-92 


150.33 


III 


28.22 


42.8 


57-67 


72.86 


88.35 


104.15 


120.26 


136.67 


153-4 


"1 


28.84 


43-71 


58.9 


74-39 


90.19 


106.3 


122.71 


139-44 


156.44 


III 


29-45 


44.64 


60.13 


75-93 


92.04 


108.45 


125.18 


142.18 


159-54 


12 


30.06 


45-55 


61.35 


77.46 


93-6 


1 10.6 


127.6 


144.96 


162.6 



Weight of Cast Iron 


Pipes 12 Inches Long, from i^ to I J Inch 


Thick. 


D. of B. 


1% Inch. 


xy^ Inch. 


D. of B. 


1% Inch. 


1% Inch. 


D. of B. 


1% Inch. 


ly^ Inch. 


Inch. 


lbs. 


lbs. 


Inch. 


lbs. 


lbs. 


Inch. 


lbs. 


lbs. 


A 


48.94 


55-22 


51 


9596 


106.77 


9 


140.06 


154-64 


2* 


52-30 


58.9 


6 


99-56 


110.44 


9i 


143-43 


158.3 


23 


55-68 


62.58 


6i 


102.92 


II4.I3 


9i 


146.8 


161.99 


3 


59-06 


66.27 


6i 


106.31 


II7.81 


9l 


150.18 


165.67 


^\ 


62.43 


69-95 


6f 


109.68 


121.49 


10 


153-55 


169.35 


^h 


65.81 


73-63 


7 


113-05 


125.17 


loi 


156.92 


173-03 


3f 


69.18 


77-31 


7i 


116.43 


128.86 


loj 


160.3 


176.71 


4 


72.56 


81. 


71 


II9.81 


132.54 


io| 


163.67 


180.4 


44 


75-99 


84-73 


7l 


123.18 


136.22 


II 


167.06 


184.06 


4^ 


79-3 


88.35 


8 


126.55 


139.89 


Hi 


170.4 


187.76 


4| 


82.68 


92.04 


8i 


129.92 


143-58 


II? 


173-8 


191.44 


5 


86.05 


95-72 


8^ 


133-53 


147-49 


Ilf 


177.18 


195.12 


54 


89-44 


99.41 


8if 


136.68 


150.94 


12 


180.54 


198.8 


5=^ 


92.81 


102.86 















114 







I^ound Cast h 


on Twelve Inches J^ong. 






Size. 


Weight. 


Size. 


Weight. 


Size. 


Weight. 


Size. 


Weight. 


Size. 


Weight. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


h 


.61 


2i 


12.42 


4 


39-27 


51 


81.14 


9 


198.79 


8" 


•95 


A 


I3-«4 


4r 


41.76 


5^ 


84.71 


9] 


210. 




1.38 


2 2 


15-33 


4? 


44.27 


6 


88.35 


9^ 


221.5 


8" 


1.87 


2| 


16.91 


4- 


46.97 


6i 


95-87 


9if 


233-34 


I 


2.45 


2f 


18.56 


4- 


49-7 


6^ 


103.69 


10 


245-43 


I^ 


31 


n 


20.28 


4* 


52-5 


6| 


III. 82 


loi 


257.86 


li 


3-«S 


3 


22.08 


4t 


55-37 


7 


120.26 


10^ 


270.59 


a 


4.64 


3^ 


23.96 


4h 


58.32 


7i 


129. 


10^ 


283.63 


I.^ 


5-52 


3i 


25.92 


5 


61.35 


7* 


138.05 


II 


296.97 


I-^ 


6.48 


3f 


27-95 


S^ 


64.46 


7f 


147.41 


iii 


310.63 


I| 


7-51 


3^ 


30.06 


5i 


67.64 


8 


157.08 


iii 


324-59 


H 


8.62 


3^ 


32.25 


5f 


70.09 


8i 


167.05 


iif 


338.85 


2 


9.81 


3f 


34-51 


5^: 


74.24 


8<^ 


177. 1 


12 


353-43 


2k 


11.08 


3i 


3^-«5 


^% 


77-65 


8if 


187.91 











Square Cast h 


^w Twelve Inches Long. 






Size. 


Weight. 


Size. 


Weight. 


Size. 


Weight. 


Size. 


Weight. 


Size. 


Weight. 


'Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


Inch. 


lbs. 


^ 


.78 


2i 


15.81 


4 


50. 


5f 


103.32 


9 


253-12 


f 


1.22 


2* 


17.62 


4^ 


53-14 


5^ 


107.86 


9} 


267.38 


1 


1-75 


z\ 


19-53 


4i 


56.44 


6 


II2.5 


9* 


282. 


k 


2-39 


2| 


21-53 


4^ 


59.81 


6i 


122.08 


9? 


297.07 


\ 


3.12 


2-4 


23-63 


47 


63.28 


6f 


132.03 


10 


312.5 


i^ 


3-95 


28 


25-83 


4- 


66.84 


6if 


142.38 


10} 


328.32 


\\ 


4.88 


3 


28.12 


4f 


70.5 


7 


153.12 


10* 


344.53 


if 


5-9 


3^ 


30.51 


4ff 


74.26 


7] 


164.25 


10^ 


361.13 


i^ 


7-03 


3i 


ZZ- 


5 


78.12 


7^ 


175-78 


II 


378.12 


\\ 


8.25 


3t 


35-59 


5A 


82.08 


7? 


187.68 


II] 


395.5 


if 


9-57 


3* 


38-28 


54 


86.13 


8 


200. 


iM 


413.28 


\\ 


10.98 


3t 


41.06 


5* 


90.28 


8i 


212.56 


III 


431-44 


2 


12.5 


3if 


43-94 


5'- 


94-53 


84 


225.78 


12 


450. 


2i 


14.U 


3i 


46.92 


5t 


98.87 


8| 


23925 







115 



Flat Cast Iron Twelve Inches Long, \ to l Inch Thick. 



mdth of 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


Iron. 


^ 


% 


V', 


H 


% 


% 


I 


Inch. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


2 


1.56 


2.34 


3.12 


3-9 


4.68 


546 


6.25 


2i 


1-75 


2.63 


3-51 


4-39 


5-27 


6.15 


7-03 


2^ 


1-95 


2.92 


3-9 


4.88 


5.85 


6.83 


7.81 


2f 


2.14 


3.22 


4.29 


5-37 


6.44 


7-51 


8.59 


3 


2.34 


.3..^! 


4.68 


5-85 


7-03 


8.2 


9-37 


3i - 


2-53 


3.8 


5-07 


6.34 


7.61 


8.88 


10.15 


3^ 


2.73 


4.1 


546 


6.83 


8.2 


9-57 


10.93 


3l 


2-93 


4-39 


5-85 


7-32 


8.78 


10.25 


II. 71 


4 


3.12 


4.68 


6.25 


7.81 


9-37 


10.93 


12.5 


4i 


3-32 


4-97 


6.64 


8.3 


9.96 


11.62 


13.28 


4^ 


351 


5-27 


7.03 


8.78 


10.54 


12.3 


14.06 


4f 


371 


5-56 


7.42 


9.27 


II. 13 


12.98 


14.84 


5 


3-9 


5.86 


7.81 


9.76 


11.71 


13-67 


15.62 


5i 


41 


6.15 


8.2 


10.25 


12.3 


14-35 


16.4 


S^ 


4.29 


6.44 


8.59 


10.74 


12.89 


15-03 


17.18 


5f 


4-49 


6.73 


8.98 


11.23 


13.46 


15-72 


17.96 


6 


4.68 


703 


9-37 


11.71 


14.06 


16.4 


18.75 



Weight of a Superficial Foot of Cast Iron from \ to 2 Inches Thick. 



Thickness. 



Wt. 



lbs. 

9-37 



% 



lbs. 
14.06 



y^ 



lbs. 

18.75 



lbs. 
!3-43 



lbs. 
28.12 



lbs. 

32.8 



lbs. 

37-5 



lbs. 
42.18 



Thickness. 



Wt. 



46.87 



51.56 



lbs. 
56.25 



x% 



lbs. 
60.93 



lbs. 

65.62 



1% 



lbs. 
70.31 



lbs. 

75- 



116 



Weight of Square Lead Twelve Inches Long, from 1 to ^ Inches Square. 


Size. 


I in. 


^Ys 


^^4 


-% 


^Y2 


X»/8 


^^ 


^Yb 


2 


Wt. 


lbs, 
4-93 


lbs. 

6.25 


lbs. 

7.71 


lbs. 

9-33 


lbs. 

II. II 


lbs. 
13.04 


lbs. 
15.12 


lbs. 

1736 


lbs, 

19.75 




Size. 


2^ 


2Ji 


2% 


2>^ 


^Ys 


23^ 


^Ys 


3 




Wt. 


lbs. 

22.29 


lbs. 

25. 


lbs. 

27.8 


lbs. 

30.86 


lbs. 

34.02 


lbs. 

37.34 


lbs. 

40.81 


lbs. 
44.44 




Weight of Round Lead Twelve Inches Long^from l to $ Inches Diameter. 


Size. 


I in. 


_^Ys 


l)^ 1% 


^K 


1% 


^% 


x% 


2 


Wt. 


lbs. 
3.87 


lbs. 

4.9 


lbs. lbs. 
6.06 7.33 


lbs. 
8.72 


lbs. 

10.24 


lbs. 

11.87 


lbs. 


lbs. 

15.51 




Size. 


^Ys 


2>i 


^% 


^Y2 


^Ys 


2% 


-% 


3 




Wt. 


lbs. 

17.51 


lbs. 

19.63 


lbs. 
21.8 


lbs. 

24.24 


lbs. 

26.72 


lbs. 
29.33 


lbs. 

32.05 


lbs. 

34.9 




Binary and Decidual Fractions. 



eV 



i^ 



=.015625 
=.03125 

=: .0468 7 5 
= .0625 
= .078125 
= .09375 
= .109375 
= .125 
= .140625 
= .15625 
= .171875 
= .1875 
= .203125 

= .21875 
= .234375 
= .25 
= .265625 
= .28125 
= .296875 
= .3125 
= .328125 

= .34375 



M 



11 
If 



=.359375 
=.375 . 
=.390625 
=.40625 
= 421875 
=.4375 
=.453125 
= 46875 

=.484375 

=.5 

=.515625 

=.53125 

=.546875 

=.5625 

= 578125 

=.59375 

=.609375 

=.625 

=.640625 

= 65625 

=.671875 



If 



H =-6875 
= 703125 

=.71875 
=.734375 
f =.75 
=.765625 
=.78125 
= 796875 

II =.8125 
=.828125 
=.84375 
=.859375 
I =.875 
=.890625 
=.90625 
= 921875 

If =-9375 
=•953125 
=.96875 
=•984375 



117 





Distances at which to open a i 


ft. Rule to obtain a given Angle. 


Angle. 


Distance. 


Angle. 


Distance. 


Angle. 


Distance. 


Angle. 


Distance. 


Angle. 


Distance. 


Deg. 


Inches 


Deg. 


Inches 


Deg. 


Inches 


Deg. 


Inches 


! Deg. 


Inches 




.2 


19 


3-96 


Zl 


7-^^ 


55 


11.08 


73 


14.28 


2 


•42 


20 


4.17 


38 


7.81 


56 


11.27 


74 


14.44 


3 


•63 


21 


4-37 


39 


8.01 


57 


11-45 


75 


14.61 


4 


.84 


22 


4.58 


40 


8.20 


58 


11.64 


76 


14.78 


5 


1.05 


23 


4.78 


41 


8.40 


59 


11.82 


77 


14.94 


6 


1.26 


24 


4-99 


42 


8.60 


60 


12.00 


78 


I5.II 


7 


1-47 


25 


5-19 


43 


8.80 


61 


12.18 


79 


15-27 


8 


1.67 


26 


540 


44 


8.99 


62 


12.36 


80 


15-43 


9 


1.88 


27 


5.60 


45 


9.18 


63 


12.54 


81 


15-59 


lO 


2.09 


28 


5.81 


46 


9-38 


64 


12.72 


82 


15-75 


II 


2.30 


29 


6.01 


47 


9-57 


65 


12.90 


^Z 


1590 


12 


2.51 


30 


6.21 


48 


9.76 


66 


13.07 


84 


16.06 


13 


2.72 


31 


6.41 


49 


9-95 


67 


13-25 


85 


16.21 


14 


2.92 


32 


6.62 


50 


10.14 


68 


13.42 


86 


16.37 


15 


3.13 


33 


6.82 


51 


IO-33 


69 


13-59 


87 


16.52 


i6 


3-34 


34 


7.02 


52 


10.52 


70 


13-77 


88 


16.67 


17 


3-55 


35 


7.22 


53 


10.71 


71 


13-94 


89 


16.82 


i8 


3-75 


36 


7.42 


54 


10.90 


72 


14.11 


90 


16.97 



118 



French Metre reduced to Inches. 



Metre. 


1 


ii 


Metre. Inches. 


Feet. 


.001587 


= tV 




.001 = .03937 = 


.00328 


.00317 


= i- 


2 = 


.002 == 


07874 = 


.00656 


.00476 


= ¥ 


3 = 


.003 = 


11811 = 


.00984 


.00635 


= } 


4 = 


.004 = 


15748 = 


.01312 


.00794 


5 


5 = 


-005 = 


19685 = 


.01641 


.00952 


- 1 


6 = 


.006 = 


23622 = 


01969 


.0111 1 


= A 


7 = 


.007 = 


2756 = 


02397 


.01270 


= \ 


8 = 


.008 = 


31497 = 


02625 


.01429 
.01587 


=f 


9 = 


•009 = -35434 = 


02953 


.01746 


— : '■■ 








.01905 


= 'i 


u| 






.02064 


= lt 


I = 


01 = -3937 = 


0328 


.02222 


= i 


2 = 


02 = .7874 = 


0656 


.02381 


= if 


3 = 


03 = i.i8ii = 


0984 


.02540 


= I 


4 = 


04 = 1.5748 = 


I3I2 


.05078 


= 2 


5 = 


05 = 1.9685 = 


1 641 


.0762 


= 3 


i 6 = 


06 = 2.3622 = 


1969 


.1016 


= 4 


i 7 = 


07 = 2.756 = 


2397 


.1270 


-6 ' 


1 8 = 


08 = 3.1497 ^ 


2625 


-1524 
.1778 


= 7 i 


9 = 


09 = 3-5434 = - 


2953 


.2032 


= 8 : 


^i 






.2286 


= 9 


P| 






.2540 


= 10 


I = . 


I = 3.9371 = • 


3281 


.2794 


= II 


2 = . 


2 = 7-8742 == . 


6562 


.3048 


= 12 


3 = • 


3 = 11.8112 = . 


9843 






4 = - 


4 =15-7483 =1. 


3124 






5 = . 


5 =19.6854 =1. 


6404 






6 = . 


6 =23.6225 =1. 


9685 






7 = - 


7 =27.5596 =2. 


3966 






8 = . 


8 =31.4966 =2. 


6247 






9 == • 


9 =35-4337 =2. 


9528 


The Metre = 


3.280899 


2 Feet (.\bout 39! In 


CHES). 



119 



PLATES OF GEAR TEETH 



13 ir r. 




14 i'J p. 



A 



15 11' P 


1 


\ 


R. 

1 









16 to 17 1'.' F 



f 



\ 



18 to 19 1." P. 20 to 21 1." P 




:\ 



1-81 



22 to 24 r: p. 25 toS 



1-34 



32 to 35 1'.' P 




[ 



1-07 



7 1." P. 




to 31 1'.' P- 



36 to 41 I'J P. 42 to47i:' P. 



48to62i:'P. 63 to 130 1'.' P' 131 to 800 1.' P 



i 



\ 



FULL SIZE GEAR TEETH. 
From Prof. S. IV. Johnson's Templet Odontograph. 



13 lUr p. 14 lUi' p. ^ ^ ^Y'' ^ 



A 



2-25 



16 to 17 IHl' P. 



18 to 19 IHl' P. 20 to 21 IHi' P 



3-10 



\ 



f 



2-26 



L -1 



22 to 24 


lU." p. 




/ 

•45 


\ 




j 


1-67 




I 











2£ 


*to2', 

1 

•46 


m'.' 


p. 




1-34 






1 




\ 











28 to 31 IHl' P 




32 to 35 IH'.' P 



36 to 4 



r\ L 



1^05 



\ 1 



IHi' P. 42 to 47 IH'' P 



A 




FULL SIZE GEAR TEETH. 
from Prof. S. W. RobinsoJi s Tetnplet Odontograph. 



14 31' r. 



IS 21' P. 



/ 

■G4 


\ 


-7-G2 


/ 







IG to 17 s." r. 




18 to 19 2'.' r. 




20 to 21 21' r. 



22 to 24 2." P. 



2-68 



FULL SIZE GEAR TEETH. 
J'rom Prof. S. IV. Robinson's Templet Odontograph. 



14: 5." r. 




FULL SIZE GEAR TEETH. 

From Prof. S. IV. Robinson^ s Te/nplef Odontograpk. 



14 2w: p. 



IS 2^:' r 



-9-52 



16 to 17 214'.' F 





FULL SIZE GEAR TEETH. 
Frof/i Prof. S. W. Robinson's Templet Odontograph. 




FULL SIZE GEAR TEETH. 

From Prof. S. IV. Robinson's Templet Odontograph. 



20 to 21 2'^il' r. 



22 to 24 2H:' p. 




FULL SIZE GEAR TEETH. 
J^rom Prof. S. W. Robinson's Temph't Odontograph 




FULL SIZE GEAR TEETH. 
I^rom Prof. S. W. Robinson's Templet Odontograph. 



20 to 21 




FULL SIZE GEAR TEETH. 

Fro/?i Prof. S. W. Robinson's Templet Odontograph. 



28 to 27 2': T. 



28 to 31 2'.' P. 



32 to 3S 2': P. 



i 


\ 




1-68 

/ 




\ 









36 to 41 21' P. 



42 to 47 2. P. 



48 to 62 2'.' P. 




FULL SIZE GEAR TEETH. 
From Prof. S. IV. Robinson's Templet Ochmtograph. 



25 to 2 



iSHl' P. 




32 to 35 2H" P 




FULL SIZE GEAR TEETH. 
From Prof. S. IV. Robinson's Templet Odoniograph. 



2 S to 27 m :' p. 2S to 31 IH': r. 32 to 3d mi' P 




36 to 41 IW: r. 42 to 47 1%'.' P. 48 to 62 1%'.' P. 




63 to 130 IHl' P. 



(■ 


\ 




1-00 

/ 




\ 









131 to 800 IH'.' P. 




FULL SIZE GEAR TEETH. 
Froffi Prof. S. IV, Robinsoiis Temp/et Odontograph. 




43 to 47 2H': F 




FULL SIZE GEAR TEETH. 
From Prof. S. IV. Robinson's Templet Odontograph. 



r 




FULL SIZE GEAR TEETH. 
From Prof. S. W. Robinson's Templet Odontography 



3G to 41 IHl' P. 42 to 47 114!' F. ^^ '» CJ? IVi'.' T 



63 t o ISO ih : r. 131 to soo mr i 




IS to 10 m." p. 20 to 21 my r. 22 to 24 ih'.' p. 



317 



FULL SIZE GEAR TEETH. 
Frojn Prof. S. PV. Robinson s Templet Odontograph. 



42 to 47 2H." P. 




4.9 to €2 2Ml' P. 




G3 to ISO 2H:' p. 




FULL SIZE GEAR TEETH. 
/'rofft Prof. S. W. Robinson's Templet Odontograph. 



48 to G2 IH'.' P. 63 to 130 IH'.' P. ^31 to sSo IM'.' JP. 




14 IH" P. i^ ly^" P' ^^ <o 17 IH '.' P 



5-02 



18 to 



19 IH- P. 20 to 21 1%': P. 22 to 24 IH 'J P 



J72 



2-70 



2-01 



L i 



25 to 



27 m': p. 28 to sir ly^: p. 32 t o ssi ih: ' p. 




FULL SIZE GEAR TEETH. 
from Prof. S. W, Robinson's Templet Odontograph. 



42 to 47 2H'' P 



4S to 62 2H'.' r. 





P'ULL SIZE GEAR TEETH. 

From Prof. S. IV. RoMnson's Templet Odontograph. 



G3 -to 13 h 2H." p 



131 to 8(io 2m:' r. 




14 2^ 


C p. 


1 

•88 


\ 


' -10-47 

\ 


\ 







15 2h:' p. 



FULL SIZE GEAR TEETH. 
From Prof. S. \V. Robinson's Templet OdotitograpK 



63 to 130 2." P 



131 to SOO 2!' P. 




FULL SIZE GEAR TEETH. 

From Prof. S. IV. Robinson's Templet Odontograph. 



